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In contrast, the World Wide Web is a global collection of documents and other resources , linked by hyperlinks and URIs. Viewing a web page on the World Wide Web normally begins either by typing the URL of the page into a web browser or by following a hyperlink to that page or resource. The web browser then initiates a series of background communication messages to fetch and display the requested page.
In the s, using a browser to view web pages—and to move from one web page to another through hyperlinks—came to be known as 'browsing,' 'web surfing' after channel surfing , or 'navigating the Web'. Early studies of this new behavior investigated user patterns in using web browsers.
One study, for example, found five user patterns: exploratory surfing, window surfing, evolved surfing, bounded navigation and targeted navigation. The browser resolves the server name of the URL example. This lookup returns an IP address such as The browser then requests the resource by sending an HTTP request across the Internet to the computer at that address.
The content of the HTTP request can be as simple as two lines of text:. The computer receiving the HTTP request delivers it to web server software listening for requests on port If the webserver can fulfill the request it sends an HTTP response back to the browser indicating success:.
Many web pages use HTML to reference the URLs of other resources such as images, other embedded media, scripts that affect page behaviour, and Cascading Style Sheets that affect page layout. As it receives their content from the web server, the browser progressively renders the page onto the screen as specified by its HTML and these additional resources. Web browsers receive HTML documents from a web server or from local storage and render the documents into multimedia web pages.
HTML describes the structure of a web page semantically and originally included cues for the appearance of the document. With HTML constructs, images and other objects such as interactive forms may be embedded into the rendered page. HTML provides a means to create structured documents by denoting structural semantics for text such as headings, paragraphs, lists, links , quotes and other items.
HTML elements are delineated by tags , written using angle brackets. Browsers do not display the HTML tags, but use them to interpret the content of the page. HTML can embed programs written in a scripting language such as JavaScript , which affects the behavior and content of web pages. Inclusion of CSS defines the look and layout of content. Most web pages contain hyperlinks to other related pages and perhaps to downloadable files, source documents, definitions and other web resources.
Such a collection of useful, related resources, interconnected via hypertext links is dubbed a web of information. The hyperlink structure of the web is described by the webgraph : the nodes of the web graph correspond to the web pages or URLs the directed edges between them to the hyperlinks.
Over time, many web resources pointed to by hyperlinks disappear, relocate, or are replaced with different content. This makes hyperlinks obsolete, a phenomenon referred to in some circles as link rot, and the hyperlinks affected by it are often called dead links.
The ephemeral nature of the Web has prompted many efforts to archive websites. The Internet Archive , active since , is the best known of such efforts. Many hostnames used for the World Wide Web begin with www because of the long-standing practice of naming Internet hosts according to the services they provide. The hostname of a web server is often www , in the same way that it may be ftp for an FTP server , and news or nntp for a Usenet news server.
The use of www is not required by any technical or policy standard and many web sites do not use it; the first web server was nxoc Many established websites still use the prefix, or they employ other subdomain names such as www2 , secure or en for special purposes. Many such web servers are set up so that both the main domain name e. The use of a subdomain name is useful for load balancing incoming web traffic by creating a CNAME record that points to a cluster of web servers.
Since, currently, only a subdomain can be used in a CNAME, the same result cannot be achieved by using the bare domain root. When a user submits an incomplete domain name to a web browser in its address bar input field, some web browsers automatically try adding the prefix "www" to the beginning of it and possibly ".
This feature started appearing in early versions of Firefox , when it still had the working title 'Firebird' in early , from an earlier practice in browsers such as Lynx. In English, www is usually read as double-u double-u double-u. Stephen Fry, in his "Podgrams" series of podcasts, pronounces it wuh wuh wuh. Tim Berners-Lee's web-space states that World Wide Web is officially spelled as three separate words, each capitalised, with no intervening hyphens.
Use of the www prefix has been declining, especially when Web 2. They specify the communication protocol to use for the request and response. A web page also written as webpage is a document that is suitable for the World Wide Web and web browsers. A web browser displays a web page on a monitor or mobile device. The term web page usually refers to what is visible, but may also refer to the contents of the computer file itself, which is usually a text file containing hypertext written in HTML or a comparable markup language.
Typical web pages provide hypertext for browsing to other web pages via hyperlinks , often referred to as links. Web browsers will frequently have to access multiple web resource elements, such as reading style sheets , scripts , and images, while presenting each web page. On a network, a web browser can retrieve a web page from a remote web server. The web server may restrict access to a private network such as a corporate intranet. A static web page is delivered exactly as stored, as web content in the web server's file system.
In contrast, a dynamic web page is generated by a web application , usually driven by server-side software. Dynamic web pages are used when each user may require completely different information, for example, bank websites, web email etc. Consequently, a static web page displays the same information for all users, from all contexts, subject to modern capabilities of a web server to negotiate content-type or language of the document where such versions are available and the server is configured to do so.
A server-side dynamic web page is a web page whose construction is controlled by an application server processing server-side scripts. In server-side scripting, parameters determine how the assembly of every new web page proceeds, including the setting up of more client-side processing. A client-side dynamic web page processes the web page using JavaScript running in the browser. The same client-side techniques can then dynamically update or change the DOM in the same way.
A dynamic web page is then reloaded by the user or by a computer program to change some variable content. The updating information could come from the server, or from changes made to that page's DOM. This may or may not truncate the browsing history or create a saved version to go back to, but a dynamic web page update using Ajax technologies will neither create a page to go back to nor truncate the web browsing history forward of the displayed page.
Using Ajax technologies the end user gets one dynamic page managed as a single page in the web browser while the actual web content rendered on that page can vary. Dynamic HTML, or DHTML, is the umbrella term for technologies and methods used to create web pages that are not static web pages , though it has fallen out of common use since the popularization of AJAX , a term which is now itself rarely used.
JavaScript is a scripting language that was initially developed in by Brendan Eich , then of Netscape , for use within web pages. Client-side script is delivered with the page that can make additional HTTP requests to the server, either in response to user actions such as mouse movements or clicks, or based on elapsed time. The server's responses are used to modify the current page rather than creating a new page with each response, so the server needs only to provide limited, incremental information.
Multiple Ajax requests can be handled at the same time, and users can interact with the page while data is retrieved. Web pages may also regularly poll the server to check whether new information is available. A website [47] is a collection of related web resources including web pages , multimedia content, typically identified with a common domain name , and published on at least one web server.
Notable examples are wikipedia. A website may be accessible via a public Internet Protocol IP network, such as the Internet , or a private local area network LAN , by referencing a uniform resource locator URL that identifies the site. Websites can have many functions and can be used in various fashions; a website can be a personal website , a corporate website for a company, a government website, an organization website, etc.
Websites are typically dedicated to a particular topic or purpose, ranging from entertainment and social networking to providing news and education. All publicly accessible websites collectively constitute the World Wide Web, while private websites, such as a company's website for its employees, are typically a part of an intranet. They may incorporate elements from other websites with suitable markup anchors.
The user's application, often a web browser , renders the page content according to its HTML markup instructions onto a display terminal. Hyperlinking between web pages conveys to the reader the site structure and guides the navigation of the site, which often starts with a home page containing a directory of the site web content. Some websites require user registration or subscription to access content.
Examples of subscription websites include many business sites, news websites, academic journal websites, gaming websites, file-sharing websites, message boards , web-based email , social networking websites, websites providing real-time price quotations for different types of markets, as well as sites providing various other services. End users can access websites on a range of devices, including desktop and laptop computers , tablet computers , smartphones and smart TVs.
A web browser commonly referred to as a browser is a software user agent for accessing information on the World Wide Web. To connect to a website's server and display its pages, a user needs to have a web browser program. This is the program that the user runs to download, format, and display a web page on the user's computer. In addition to allowing users to find, display, and move between web pages, a web browser will usually have features like keeping bookmarks, recording history, managing cookies see below , and home pages and may have facilities for recording passwords for logging into web sites.
A Web server is server software , or hardware dedicated to running said software, that can satisfy World Wide Web client requests. A web server can, in general, contain one or more websites. A web server processes incoming network requests over HTTP and several other related protocols. The primary function of a web server is to store, process and deliver web pages to clients. Pages delivered are most frequently HTML documents , which may include images , style sheets and scripts in addition to the text content.
A user agent , commonly a web browser or web crawler , initiates communication by making a request for a specific resource using HTTP and the server responds with the content of that resource or an error message if unable to do so. The resource is typically a real file on the server's secondary storage , but this is not necessarily the case and depends on how the webserver is implemented.
While the primary function is to serve content, full implementation of HTTP also includes ways of receiving content from clients. This feature is used for submitting web forms , including uploading of files. This means that the behavior of the webserver can be scripted in separate files, while the actual server software remains unchanged. Usually, this function is used to generate HTML documents dynamically "on-the-fly" as opposed to returning static documents.
The former is primarily used for retrieving or modifying information from databases. The latter is typically much faster and more easily cached but cannot deliver dynamic content. Web servers can also frequently be found embedded in devices such as printers , routers , webcams and serving only a local network. The web server may then be used as a part of a system for monitoring or administering the device in question.
This usually means that no additional software has to be installed on the client computer since only a web browser is required which now is included with most operating systems. An HTTP cookie also called web cookie , Internet cookie , browser cookie , or simply cookie is a small piece of data sent from a website and stored on the user's computer by the user's web browser while the user is browsing.
Cookies were designed to be a reliable mechanism for websites to remember stateful information such as items added in the shopping cart in an online store or to record the user's browsing activity including clicking particular buttons, logging in , or recording which pages were visited in the past. They can also be used to remember arbitrary pieces of information that the user previously entered into form fields such as names, addresses, passwords, and credit card numbers.
Cookies perform essential functions in the modern web. Perhaps most importantly, authentication cookies are the most common method used by web servers to know whether the user is logged in or not, and which account they are logged in with. Without such a mechanism, the site would not know whether to send a page containing sensitive information or require the user to authenticate themselves by logging in.
The security of an authentication cookie generally depends on the security of the issuing website and the user's web browser , and on whether the cookie data is encrypted. Security vulnerabilities may allow a cookie's data to be read by a hacker , used to gain access to user data, or used to gain access with the user's credentials to the website to which the cookie belongs see cross-site scripting and cross-site request forgery for examples.
Tracking cookies, and especially third-party tracking cookies , are commonly used as ways to compile long-term records of individuals' browsing histories — a potential privacy concern that prompted European [50] and U. Google Project Zero researcher Jann Horn describes ways cookies can be read by intermediaries , like Wi-Fi hotspot providers. He recommends using the browser in incognito mode in such circumstances. A web search engine or Internet search engine is a software system that is designed to carry out web search Internet search , which means to search the World Wide Web in a systematic way for particular information specified in a web search query.
The search results are generally presented in a line of results, often referred to as search engine results pages SERPs. The information may be a mix of web pages , images, videos, infographics, articles, research papers, and other types of files.
Some search engines also mine data available in databases or open directories. Unlike web directories , which are maintained only by human editors, search engines also maintain real-time information by running an algorithm on a web crawler.
Internet content that is not capable of being searched by a web search engine is generally described as the deep web. The deep web, [54] invisible web , [55] or hidden web [56] are parts of the World Wide Web whose contents are not indexed by standard web search engines.
The opposite term to the deep web is the surface web , which is accessible to anyone using the Internet. Bergman is credited with coining the term deep web in as a search indexing term. The content of the deep web is hidden behind HTTP forms, [59] [60] and includes many very common uses such as web mail , online banking , and services that users must pay for, and which is protected by a paywall , such as video on demand , some online magazines and newspapers, among others. The content of the deep web can be located and accessed by a direct URL or IP address , and may require a password or other security access past the public website page.
A web cache is a server computer located either on the public Internet or within an enterprise that stores recently accessed web pages to improve response time for users when the same content is requested within a certain time after the original request. Most web browsers also implement a browser cache by writing recently obtained data to a local data storage device.
HTTP requests by a browser may ask only for data that has changed since the last access. Web pages and resources may contain expiration information to control caching to secure sensitive data, such as in online banking , or to facilitate frequently updated sites, such as news media. Even sites with highly dynamic content may permit basic resources to be refreshed only occasionally.
Web site designers find it worthwhile to collate resources such as CSS data and JavaScript into a few site-wide files so that they can be cached efficiently. Enterprise firewalls often cache Web resources requested by one user for the benefit of many users. Some search engines store cached content of frequently accessed websites.
For criminals , the Web has become a venue to spread malware and engage in a range of cybercrimes , including but not limited to identity theft , fraud , espionage and intelligence gathering. Proposed solutions vary. Every time a client requests a web page, the server can identify the request's IP address. Web servers usually log IP addresses in a log file. Also, unless set not to do so, most web browsers record requested web pages in a viewable history feature, and usually cache much of the content locally.
Unless the server-browser communication uses HTTPS encryption, web requests and responses travel in plain text across the Internet and can be viewed, recorded, and cached by intermediate systems. Another way to hide personally identifiable information is by using a virtual private network. A VPN encrypts online traffic and masks the original IP address lowering the chance of user identification. When a web page asks for, and the user supplies, personally identifiable information—such as their real name, address, e-mail address, etc.
If the website uses HTTP cookies , username, and password authentication, or other tracking techniques, it can relate other web visits, before and after, to the identifiable information provided. In this way, a web-based organization can develop and build a profile of the individual people who use its site or sites. It may be able to build a record for an individual that includes information about their leisure activities, their shopping interests, their profession, and other aspects of their demographic profile.
These profiles are of potential interest to marketers, advertisers, and others. Depending on the website's terms and conditions and the local laws that apply information from these profiles may be sold, shared, or passed to other organizations without the user being informed. For many ordinary people, this means little more than some unexpected e-mails in their in-box or some uncannily relevant advertising on a future web page.
For others, it can mean that time spent indulging an unusual interest can result in a deluge of further targeted marketing that may be unwelcome. Law enforcement, counter-terrorism, and espionage agencies can also identify, target, and track individuals based on their interests or proclivities on the Web. Social networking sites usually try to get users to use their real names, interests, and locations, rather than pseudonyms, as their executives believe that this makes the social networking experience more engaging for users.
On the other hand, uploaded photographs or unguarded statements can be identified to an individual, who may regret this exposure. Employers, schools, parents, and other relatives may be influenced by aspects of social networking profiles, such as text posts or digital photos, that the posting individual did not intend for these audiences.
Online bullies may make use of personal information to harass or stalk users. Modern social networking websites allow fine-grained control of the privacy settings for each posting, but these can be complex and not easy to find or use, especially for beginners. With modern and potential facial recognition technology , it may then be possible to relate that face with other, previously anonymous, images, events, and scenarios that have been imaged elsewhere.
Due to image caching, mirroring, and copying, it is difficult to remove an image from the World Wide Web. Web standards include many interdependent standards and specifications, some of which govern aspects of the Internet , not just the World Wide Web. Even when not web-focused, such standards directly or indirectly affect the development and administration of websites and web services. Considerations include the interoperability , accessibility and usability of web pages and web sites.
Web standards are not fixed sets of rules but are constantly evolving sets of finalized technical specifications of web technologies. It is crucial to distinguish those specifications that are under development from the ones that already reached the final development status in the case of W3C specifications, the highest maturity level. There are methods for accessing the Web in alternative mediums and formats to facilitate use by individuals with disabilities.
These disabilities may be visual, auditory, physical, speech-related, cognitive, neurological, or some combination. Accessibility features also help people with temporary disabilities, like a broken arm, or ageing users as their abilities change. The World Wide Web Consortium claims that it is essential that the Web be accessible, so it can provide equal access and equal opportunity to people with disabilities.
Access by everyone regardless of disability is an essential aspect. The W3C Internationalisation Activity assures that web technology works in all languages, scripts, and cultures. From Wikipedia, the free encyclopedia. System of interlinked hypertext documents accessed over the Internet. For uses of web, see Web disambiguation. For the first web software, see WorldWideWeb. Not to be confused with the Internet. Main article: History of the World Wide Web. Main article: HTML. Main article: Web page.
Let's look at those steps in more detail. First, a web server has to store the website's files, namely all HTML documents and their related assets, including images, CSS stylesheets, JavaScript files, fonts, and video.
Technically, you could host all those files on your own computer, but it's far more convenient to store files all on a dedicated web server because:. For all these reasons, finding a good hosting provider is a key part of building your website. Examine the various services companies offer. Choose one that fits your needs and budget.
Services range from free to thousands of dollars per month. You can find more details in this article. Once you have web hosting service, you must upload your files to your web server. As its name implies, HTTP specifies how to transfer hypertext linked web documents between two computers. A Protocol is a set of rules for communication between two computers. HTTP is a textual, stateless protocol. Neither the server nor the client remember previous communications.
For example, relying on HTTP alone, a server can't remember a password you typed or remember your progress on an incomplete transaction. You need an application server for tasks like that. We'll cover that sort of technology in other articles. HTTP provides clear rules for how a client and server communicate. We'll cover HTTP itself in a technical article later. For now, just be aware of these things:.
Roughly speaking, a server can serve either static or dynamic content. Remember that the term static means "served as-is". Static websites are the easiest to set up, so we suggest you make your first site a static site. The term dynamic means that the server processes the content or even generates it on the fly from a database. This approach provides more flexibility, but the technical stack is more complex, making it dramatically more challenging to build a website.
There are so many application server technologies that it's difficult to suggest a particular one. Some application servers cater to specific website categories like blogs, wikis, or eCommerce; others are more generic. If you're building a dynamic website, take the time to choose technology that fits your needs.
Unless you want to learn web server programming which is an exciting area in itself! That's just reinventing the wheel. Skip to main content Skip to search Skip to select language Guides Common questions What is a web server? Article Actions English US.
Prerequisites: You should already know how the Internet works , and understand the difference between a web page, a web site, a web server, and a search engine. Objective: You will learn what a web server is and gain a general understanding of how it works. On the hardware side, a web server is a computer that stores web server software and a website's component files for example, HTML documents, images, CSS stylesheets, and JavaScript files. A web server connects to the Internet and supports physical data interchange with other devices connected to the web.
Using Ajax technologies the end user gets one dynamic page managed as a single page in the web browser while the actual web content rendered on that page can vary. Dynamic HTML, or DHTML, is the umbrella term for technologies and methods used to create web pages that are not static web pages , though it has fallen out of common use since the popularization of AJAX , a term which is now itself rarely used.
JavaScript is a scripting language that was initially developed in by Brendan Eich , then of Netscape , for use within web pages. Client-side script is delivered with the page that can make additional HTTP requests to the server, either in response to user actions such as mouse movements or clicks, or based on elapsed time. The server's responses are used to modify the current page rather than creating a new page with each response, so the server needs only to provide limited, incremental information.
Multiple Ajax requests can be handled at the same time, and users can interact with the page while data is retrieved. Web pages may also regularly poll the server to check whether new information is available. A website [47] is a collection of related web resources including web pages , multimedia content, typically identified with a common domain name , and published on at least one web server.
Notable examples are wikipedia. A website may be accessible via a public Internet Protocol IP network, such as the Internet , or a private local area network LAN , by referencing a uniform resource locator URL that identifies the site. Websites can have many functions and can be used in various fashions; a website can be a personal website , a corporate website for a company, a government website, an organization website, etc.
Websites are typically dedicated to a particular topic or purpose, ranging from entertainment and social networking to providing news and education. All publicly accessible websites collectively constitute the World Wide Web, while private websites, such as a company's website for its employees, are typically a part of an intranet. They may incorporate elements from other websites with suitable markup anchors. The user's application, often a web browser , renders the page content according to its HTML markup instructions onto a display terminal.
Hyperlinking between web pages conveys to the reader the site structure and guides the navigation of the site, which often starts with a home page containing a directory of the site web content. Some websites require user registration or subscription to access content. Examples of subscription websites include many business sites, news websites, academic journal websites, gaming websites, file-sharing websites, message boards , web-based email , social networking websites, websites providing real-time price quotations for different types of markets, as well as sites providing various other services.
End users can access websites on a range of devices, including desktop and laptop computers , tablet computers , smartphones and smart TVs. A web browser commonly referred to as a browser is a software user agent for accessing information on the World Wide Web. To connect to a website's server and display its pages, a user needs to have a web browser program.
This is the program that the user runs to download, format, and display a web page on the user's computer. In addition to allowing users to find, display, and move between web pages, a web browser will usually have features like keeping bookmarks, recording history, managing cookies see below , and home pages and may have facilities for recording passwords for logging into web sites. A Web server is server software , or hardware dedicated to running said software, that can satisfy World Wide Web client requests.
A web server can, in general, contain one or more websites. A web server processes incoming network requests over HTTP and several other related protocols. The primary function of a web server is to store, process and deliver web pages to clients. Pages delivered are most frequently HTML documents , which may include images , style sheets and scripts in addition to the text content. A user agent , commonly a web browser or web crawler , initiates communication by making a request for a specific resource using HTTP and the server responds with the content of that resource or an error message if unable to do so.
The resource is typically a real file on the server's secondary storage , but this is not necessarily the case and depends on how the webserver is implemented. While the primary function is to serve content, full implementation of HTTP also includes ways of receiving content from clients.
This feature is used for submitting web forms , including uploading of files. This means that the behavior of the webserver can be scripted in separate files, while the actual server software remains unchanged. Usually, this function is used to generate HTML documents dynamically "on-the-fly" as opposed to returning static documents. The former is primarily used for retrieving or modifying information from databases.
The latter is typically much faster and more easily cached but cannot deliver dynamic content. Web servers can also frequently be found embedded in devices such as printers , routers , webcams and serving only a local network. The web server may then be used as a part of a system for monitoring or administering the device in question.
This usually means that no additional software has to be installed on the client computer since only a web browser is required which now is included with most operating systems. An HTTP cookie also called web cookie , Internet cookie , browser cookie , or simply cookie is a small piece of data sent from a website and stored on the user's computer by the user's web browser while the user is browsing.
Cookies were designed to be a reliable mechanism for websites to remember stateful information such as items added in the shopping cart in an online store or to record the user's browsing activity including clicking particular buttons, logging in , or recording which pages were visited in the past.
They can also be used to remember arbitrary pieces of information that the user previously entered into form fields such as names, addresses, passwords, and credit card numbers. Cookies perform essential functions in the modern web. Perhaps most importantly, authentication cookies are the most common method used by web servers to know whether the user is logged in or not, and which account they are logged in with.
Without such a mechanism, the site would not know whether to send a page containing sensitive information or require the user to authenticate themselves by logging in. The security of an authentication cookie generally depends on the security of the issuing website and the user's web browser , and on whether the cookie data is encrypted. Security vulnerabilities may allow a cookie's data to be read by a hacker , used to gain access to user data, or used to gain access with the user's credentials to the website to which the cookie belongs see cross-site scripting and cross-site request forgery for examples.
Tracking cookies, and especially third-party tracking cookies , are commonly used as ways to compile long-term records of individuals' browsing histories — a potential privacy concern that prompted European [50] and U. Google Project Zero researcher Jann Horn describes ways cookies can be read by intermediaries , like Wi-Fi hotspot providers. He recommends using the browser in incognito mode in such circumstances. A web search engine or Internet search engine is a software system that is designed to carry out web search Internet search , which means to search the World Wide Web in a systematic way for particular information specified in a web search query.
The search results are generally presented in a line of results, often referred to as search engine results pages SERPs. The information may be a mix of web pages , images, videos, infographics, articles, research papers, and other types of files. Some search engines also mine data available in databases or open directories. Unlike web directories , which are maintained only by human editors, search engines also maintain real-time information by running an algorithm on a web crawler.
Internet content that is not capable of being searched by a web search engine is generally described as the deep web. The deep web, [54] invisible web , [55] or hidden web [56] are parts of the World Wide Web whose contents are not indexed by standard web search engines. The opposite term to the deep web is the surface web , which is accessible to anyone using the Internet.
Bergman is credited with coining the term deep web in as a search indexing term. The content of the deep web is hidden behind HTTP forms, [59] [60] and includes many very common uses such as web mail , online banking , and services that users must pay for, and which is protected by a paywall , such as video on demand , some online magazines and newspapers, among others.
The content of the deep web can be located and accessed by a direct URL or IP address , and may require a password or other security access past the public website page. A web cache is a server computer located either on the public Internet or within an enterprise that stores recently accessed web pages to improve response time for users when the same content is requested within a certain time after the original request.
Most web browsers also implement a browser cache by writing recently obtained data to a local data storage device. HTTP requests by a browser may ask only for data that has changed since the last access. Web pages and resources may contain expiration information to control caching to secure sensitive data, such as in online banking , or to facilitate frequently updated sites, such as news media. Even sites with highly dynamic content may permit basic resources to be refreshed only occasionally.
Web site designers find it worthwhile to collate resources such as CSS data and JavaScript into a few site-wide files so that they can be cached efficiently. Enterprise firewalls often cache Web resources requested by one user for the benefit of many users. Some search engines store cached content of frequently accessed websites. For criminals , the Web has become a venue to spread malware and engage in a range of cybercrimes , including but not limited to identity theft , fraud , espionage and intelligence gathering.
Proposed solutions vary. Every time a client requests a web page, the server can identify the request's IP address. Web servers usually log IP addresses in a log file. Also, unless set not to do so, most web browsers record requested web pages in a viewable history feature, and usually cache much of the content locally.
Unless the server-browser communication uses HTTPS encryption, web requests and responses travel in plain text across the Internet and can be viewed, recorded, and cached by intermediate systems. Another way to hide personally identifiable information is by using a virtual private network. A VPN encrypts online traffic and masks the original IP address lowering the chance of user identification.
When a web page asks for, and the user supplies, personally identifiable information—such as their real name, address, e-mail address, etc. If the website uses HTTP cookies , username, and password authentication, or other tracking techniques, it can relate other web visits, before and after, to the identifiable information provided. In this way, a web-based organization can develop and build a profile of the individual people who use its site or sites.
It may be able to build a record for an individual that includes information about their leisure activities, their shopping interests, their profession, and other aspects of their demographic profile. These profiles are of potential interest to marketers, advertisers, and others. Depending on the website's terms and conditions and the local laws that apply information from these profiles may be sold, shared, or passed to other organizations without the user being informed.
For many ordinary people, this means little more than some unexpected e-mails in their in-box or some uncannily relevant advertising on a future web page. For others, it can mean that time spent indulging an unusual interest can result in a deluge of further targeted marketing that may be unwelcome.
Law enforcement, counter-terrorism, and espionage agencies can also identify, target, and track individuals based on their interests or proclivities on the Web. Social networking sites usually try to get users to use their real names, interests, and locations, rather than pseudonyms, as their executives believe that this makes the social networking experience more engaging for users.
On the other hand, uploaded photographs or unguarded statements can be identified to an individual, who may regret this exposure. Employers, schools, parents, and other relatives may be influenced by aspects of social networking profiles, such as text posts or digital photos, that the posting individual did not intend for these audiences. Online bullies may make use of personal information to harass or stalk users.
Modern social networking websites allow fine-grained control of the privacy settings for each posting, but these can be complex and not easy to find or use, especially for beginners. With modern and potential facial recognition technology , it may then be possible to relate that face with other, previously anonymous, images, events, and scenarios that have been imaged elsewhere.
Due to image caching, mirroring, and copying, it is difficult to remove an image from the World Wide Web. Web standards include many interdependent standards and specifications, some of which govern aspects of the Internet , not just the World Wide Web. Even when not web-focused, such standards directly or indirectly affect the development and administration of websites and web services. Considerations include the interoperability , accessibility and usability of web pages and web sites.
Web standards are not fixed sets of rules but are constantly evolving sets of finalized technical specifications of web technologies. It is crucial to distinguish those specifications that are under development from the ones that already reached the final development status in the case of W3C specifications, the highest maturity level. There are methods for accessing the Web in alternative mediums and formats to facilitate use by individuals with disabilities. These disabilities may be visual, auditory, physical, speech-related, cognitive, neurological, or some combination.
Accessibility features also help people with temporary disabilities, like a broken arm, or ageing users as their abilities change. The World Wide Web Consortium claims that it is essential that the Web be accessible, so it can provide equal access and equal opportunity to people with disabilities. Access by everyone regardless of disability is an essential aspect.
The W3C Internationalisation Activity assures that web technology works in all languages, scripts, and cultures. From Wikipedia, the free encyclopedia. System of interlinked hypertext documents accessed over the Internet. For uses of web, see Web disambiguation. For the first web software, see WorldWideWeb.
Not to be confused with the Internet. Main article: History of the World Wide Web. Main article: HTML. Main article: Web page. Main article: Static web page. Main articles: Dynamic web page and Ajax programming. Main article: Website. Main article: Web browser. Main article: Web server. Main article: HTTP cookie. Main article: Search engine. Main article: Deep web. Main article: Internet privacy. Main article: Web standards.
Main article: Web accessibility. Engineering portal Internet portal World portal. Electronic publishing Internet metaphors Internet security Lists of websites Streaming media Web development tools Web literacy. Retrieved 9 March Retrieved 16 July Pews Research Center. Retrieved 1 August The Washington Post. Archived from the original on 9 July The World Wide Web Consortium.
Retrieved 12 February Simon and Schuster. ISBN Time Magazine. Archived from the original on 15 August Retrieved 17 May He wove the World Wide Web and created a mass medium for the 21st century. He designed it. He set it loose it on the world. And he more than anyone else has fought to keep it an open, non-proprietary and free. Twenty-First Century Books. Retrieved 15 April London: Polity Press.
The History of the Web. Retrieved 13 February Roger Clarke's Web-Site. Retrieved 15 February Retrieved 14 February Retrieved 8 March Retrieved 16 February Retrieved 17 February IGI Global. Pew Research Center. Archived from the original on 29 July Archived from the original on 9 September Archived from the original on 2 July World Wide Web Consortium. Archived from the original on 22 April Retrieved 18 April Journal of Marketing Communications. JavaScript — The definitive guide 6 ed.
JavaScript is part of the triad of technologies that all Web developers must learn: HTML to specify the content of web pages, CSS to specify the presentation of web pages, and JavaScript to specify the behaviour of web pages. Retrieved 6 July Archived from the original on 2 May Retrieved 12 May Archived from the original on 2 August Retrieved 27 July Archived 23 July at the Wayback Machine. Archived from the original on 27 June Retrieved 27 May This has no impact on the human reader of the page, but tells search engine crawlers where the page actually lives.
This way, search engines don't index the same page several times, potentially leading to it being considered as duplicate content or spam, and even removing or lowering your page from the search engine result pages. When adding such a tag, you serve the same content for both domains, telling search engines which URL is canonical.
Unlike the previous case, browser history will consider non-www and www URLs as independent entries. With these techniques, you can configure your server to respond correctly for both, the www-prefixed and the non-www-prefixed domains. It is a matter of choosing which type you want to use as your canonical location, then redirecting the other type to it.
This is a very subjective topic it could be considered a bikeshedding issue. If you wish to read deeper, please see some of the many articles on the subject. Yes , you need to choose one and stick with it. The choice of which one to have as your canonical location is yours, but if you choose one, stick with it. It will make your website appear more consistent to your users and to search engines. No , you can have two. What is important is that you are coherent and consistent with which one is the official domain.
This official domain is called the canonical name.
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