World Wide Web – Wikipedia, the free encyclopedia – ABOUT MAG 2020

World Wide Web

Site structure
HTML. XHTML. XML. XSL


Generating dynamic web pages
Active server pages. ASP.NET. JavaServer pages. PHP


On the user side
cascading style sheets. Javascript. AJAX. colors on the Internet


Data transfer
Hypertext transfer protocol. HTTPS. HTTP referrer. web server. VoiceXML. XMLHttpRequest


concepts
web design. Information Architecture. utility. availability

The first web server deployed on a computer NeXT

World Wide Web [[[[ˌinɜ:ldˌinandɪdinɛB](global and global network extensive computer network), in short site or Webhypertext. multimedia. online Information system based on standards open to the public IETF and W3C. WWW is Web service, which due to the acquired popularity, is sometimes mistakenly identified with the entire Internet, especially by novice users.

British engineer and scientist sir Tim Berners-Leecurrently director Consortium on the World Wide Web (W3C), March 12, 1989[1] published a project based on INQUIRE (application and database that he created for his own use in 1980). In it, he introduced a much more extensive information management system, which became the core of the current WWW. After some time, a Belgian scientist joined him Robert Cailliauwith whom Berners-Lee collaborated at the center CERN. On November 12, 1990, they published an official project to build the system hypertext called “World Wide Web” (in short: WWW, or even shorter: W3), operated with web browserwho uses architecture client-server[2]. The use of hypertext allowed access to various types of information over the network Connectionscalled hyperlinks – watching a website, the user can follow the posts on it hyperlinksthat transfer it to other documents or shared web pages on the web. Initially, the “World Wide Web” was based on SGML– a new browser called “DynaText“, Developed as part of the activities of the Information and Knowledge Research Institute (Information and Scholarship Research Institute) Brown University. “Dynatext” was a commercial project, licensed by CERN – but it ended up being too expensive to be used by a wider community (at the time it was an environment of high-energy physicists), because it provided a fee for each new document and for each edition[[[[take note].

The World Wide Web’s information system is designed to bring together human knowledge resources and allow colleagues in remote places to share their ideas and explore all aspects of a joint project. In the event that two projects were created independently of each other, the WWW made it possible to coordinate the work of scientists, thanks to which the two works became a coherent work. This project estimated that the navigation-only network would develop within three months and, within half a year, users could publish new materials and links to them, making the system totally universal. The service was officially launched in December 1990[[[[take note].

As the world’s first web server, Berners-Lee used the computer NeXTwhere he also created the first browser called WorldWideWeb (later changed to nexus). By Christmas 1990, Berners-Lee had built all the tools necessary to make the WWW work: web browser (who also served as editor), first web server and first WWW pagesdescribing the newly created project. On August 6, 1991, he published a brief summary of the “WorldWideWeb” project in the discussion group alt.hypertext. This date is also considered the debut of publicly available services on the Internet. The first server outside Europe was launched in Stanford Linear Accelerator Center (SLAC) in December 1992. The basic concept of hypertext comes from older projects from the 1960s, such as: Hypertext Editing System (HES) created at Brown University, Xanadu per Ted Nelson and Andries van Dam and Online system (NLS) Douglas Engelbart. Nelson and Engelbart, in turn, were inspired by the microcomputer Memex, which in 1945 was described in an essay entitled “How can we think” Vannevar Bush[[[[take note].

The advance in the project was the connection of hypertext to the Internet. In his book “Weaving the Web” Berners-Lee explains that he repeatedly suggested the possibility of combining these two technologies, but no one has ever made efforts in this regard and therefore decided to take matters into his own hands. For the project’s needs, the author developed a system of unique publicly available identifiers for network resources: “The Universal Document Identifier” (UDI), later known as Uniform Resource Locator (URL) and Uniform Resource Identifier (URI), the language used to create pages – HyperText markup language (HTML) and the protocol for sending hypertext documents Hypertext transfer protocol (HTTP)[[[[take note].

The World Wide Web had several features that set it apart from other hypertext systems available at the time, such as the use of unidirectional instead of bidirectional links. This allowed the user to switch from the current data resource to the next one without requiring a response from its owner. Compared to previous systems, this facilitated the implementation of new servers and browsers, but introduced a chronic problem of expired links (hyperlinks, links). Unlike its predecessors, as HyperCard, The World Wide Web was not marketed, enabling the development servers and published in them locations, independently and adding extensions without licensing restrictions. On April 30, 1993, CERN announced that the Internet would be available for free to anyone. In the next two months, after announcing this protocol Gopher[3] will no longer be available for free, there has been a significant decline in its popularity in favor of the free WWW. The most popular browser at the time was ViolaWWW[[[[take note].

The turning point in the history of the World Wide Web was the introduction of the browser in 1993 mosaic, operating in graphics mode. This browser was developed by the “National Center for Supercomputing Applications” team (National Center for Supercomputing Applications) in University of Illinois at Urban and Champaign (NCSA-UIUC), which was then led by By Andreessen. Mosaic was funded by the “High Performance Computing and Communication Techniques Initiative” (High-performance computing and communication initiative), created thanks to the “Law on high performance computing and communication techniques” (High Performance Computing and Communication Law) of 1991, which is one of several studies on development computer science, started by senator Wing Gore‘THE. Before the introduction of the Mosaic graphics browser, websites did not have graphics directly intertwined in the text, and the popularity of the Web was less than that of older protocols previously used on the Internet, such as Gopher or WAISgraphic interface The Mosaic browser has made the WWW by far the most popular Web service[[[[take note].

The World Wide Web Consortium (W3C) was founded by Tim Berners-Lee after he left CERN’s facilities in October 1994. The consortium was created at the MIT IT Lab (Massachusetts Institute of Technology, Computer Science Laboratory, MIT / LCS), with the help of the “Advanced Defense Research Projects Agency” (Defense Advanced Research Projects Agency, DARPA), a pioneer in the development of the Internet and European Commission. In late 1994, when the total number of sites was a fraction of the current number, many of the sites known today were already running and some of them could have inspired many contemporary people sites[[[[take note].

Thanks to the Internet connection, they started to emerge around the world web servers, creating global naming standards Internet domains. Since then, Berners-Lee has played a very active role in defining the direction for the development of network standards (such as markup languages, on which sites are created) and, in recent years, he talks about his vision Semantic Web. World Wide Web, thanks to the ease of learning the user interface, actively disseminates information over the Internet – thus playing an important role in its popularization – although these two concepts are often confused in widespread use: the World Wide Web is not the entire Internet, but only a certain application built on its base[[[[take note].

The terms: World Wide Web and Internet are often used interchangeably in everyday life. However, the World Wide Web and the Internet are not the same. The Internet is a global system of interconnected computer networks. Unlike the Web, which is one of the services that operates on the Internet, the WWW is a collection of resources and related documents, connected by hyperlinks and URLs. In summary, the Web is an application that works on the Internet. Web browsing usually starts by entering the page’s address in a web browser or providing a link to that page or a link to a specific resource. Then, the browser sends to web serverin which the page is located, a series of invisible queries to download the content of the page and display it on the screen monitor[[[[take note].

Initially, the server name (part of the URL) is decoded into IP adress using a global distributed database known as Domain Name System (DNS). An IP address is required to connect to the server. The browser calls the resource by sending a query to the server specified by the address above. For a typical website, the browser downloads it first writing HTML analyzes and sends a request to the rest of its components (photos, graphics, sounds, video, animations). The statistics that measure the popularity of the pages are usually based on the number of visits, but also on the number of queries sent to the server that have occurred.[[[[take note].

When downloading files from a web server, browsers can gradually send a page to the screen in the manner specified by the HTML code, CSS or other scripting languages. All photos and other features are included on the page that the user sees on the screen. Most sites contain hyperlinks that allow direct access to other sites associated with them, ready-to-download files, source documents, definitions and other online resources. This set of useful materials linked via hypertext links was called an “information network”. When making this network available on the Internet, Tim Berners-Lee called it the “World Wide Web” in November 1990 (initially “WorldWideWeb“But that entry was later rejected)[[[[take note].

WWW (or even shorter: W3) is the implementation of the idea of ​​an unlimited world of information. For her success, in addition to herself Internet as a physical medium, the following elements mainly consist of:

Many web addresses begin with “www” due to the old practice of naming web hosts (servers) according to the services offered. The host name of the web server is usually www, as well as ftp for FTP server be it news or nntp for information servers Usenet. These hostnames appear as subdomains in the domain name system (DNS), as in the example www.example.com. The use of these subdomains is not necessary. The world’s first web server was called nxoc01.cern.ch, and many sites exist without the WWW or other prefix, such as “www2”, “secure” etc. Subdomain prefixes have no practical meaning, these are the common names given by administrators. Many web servers are configured to use both versions of the address, the domain itself (example.com) and the subdomain (www.example.com). In practice, they direct the user to exactly the same page[[[[take note].

If you only type a specific word in your browser’s address bar, for example: Apple . openoffice the application can try to add the www prefix and end, for example, “.com”, “.org” or “.net” and will redirect us to “http://www.apple.com/“Or http://www.openoffice.org/. These features were introduced in previous versions of the browser Mozilla Firefox in early 2003. However, Microsoft he received a patent in 2008 for the same solution, only with respect to mobile devices[[[[take note].

The prefixes ‘http: //’ and ‘https: //’ must be distinguished. Hypertext transfer protocol (HTTP) and secure HTTP designate the communication protocol to be used to send and download the content of the page. The HTTP protocol is a basic element of the www structure and HTTPS adds the necessary protective layer when confidential information, such as passwords or bank details, must be sent over the public Internet. Internet browsers also automatically add this element (HTTPS) if it is omitted. General description RFC 2396 ↓ specifying the shape of the web addresses are: : //<ścieżka>?#Where is, for example, a web server (as www.example.com) and the path identifies a specific subpage. The server is processing whereas, for example, using the form, you can send data to an external search engine; therefore, the content of the displayed page depends on the feedback received. it is not sent to the server. Specifies which part of the page should be displayed to the user by default.[[[[take note].

In English, www is pronounced by singing a single string (double double double). Some user circles pronounce dub-dub-dub, although this method is not yet very common. English writer Douglas Adams he once joked in The Independent, on Sunday (1999): “As far as I know, the World Wide Web is the only expression whose abbreviated form is three times that of the full text”. The term World Wide Web is generally translated into Chinese as: wan wei wǎng, which literally means “multiple dimensions of the network”. This translation reflects the concept of the project and the premises of the website very well. Tim Berners-Lee defined the expression World Wide Web to be written as 3 separate words without any additional hyphens[[[[take note].

Computer users who save time and money, as well as those looking for comfort and entertainment are at risk of losing their privacy online. Worldwide, more than half a billion people use social networking sites, and teenagers in the Internet age are making another generation shift. with Facebook, widespread among American students, is now used by more than 70% of users in countries other than the United States. In 2009, a new testing tool was launched on the portal to personalize privacy protection, but only 20% of users started using it. The websites themselves use part of the user data entrusted to them for advertising purposes. A person using the Internet can delete the history of browsed pages, block certain cookies (cookies) and pop-upshowever, this does not provide full privacy protection[[[[take note].

The Web has become an open way for criminals to spread malware. Online cyber crimes can consist of identity theft, fraud, espionage and the collection of confidential information. An Internet connection overcomes traditional threats to the security of computer-processed data, and Google estimates that about one in ten sites may contain malicious code. Most web-based attacks occur on legitimate websites and, most of the time, as the company estimates Sophos, a producer of antivirus software, attacks are carried out in the United States, China and Russia. The most common type of threat is SQL injection. The web has also been exposed to attacks like HTML and URI cross-site scripting (XSS), which appeared with the introduction of JavaScript, has been extended to some extent by Web 2.0 and AJAX, using large amounts of scripts. Today, it is estimated that 70% of all websites are not protected against XSS attacks[[[[take note].

Over time, many of the resources published on the Internet disappear, are moved, updated or their content completely changed. This makes some links obsolete. They are called “dead links” (ang. dead links). This problem caused corrective actions to be taken and, for example, Internet Archive, operating since 1996, is currently the best known institution that deals with filing Internet resources[[[[take note].

The functioning of the World Wide Web on the Internet and the exchange of information between computers are based on many standards and technical specifications. Most of these documents are studies Consortium on the World Wide Web (W3C), led by Berners-Lee, and some of them are the work of Internet Engineering Task Force (IETF) and other organizations[[[[take note].

When we mention Internet standards, we generally deal with the following publications[[[[take note]:

  • W3C recommendations for markup languages, especially HTML and XHTML. They define the structures for interpreting hypertext documents.
  • W3C recommendations for style sheets, especially CSS.
  • standards ECMAScript (usually in JavaScript), from ECMA International.
  • W3C recommendations for modeling object documents.

Additional publications provide definitions of other basic technologies used on the World Wide Web, including:

  • Uniform Resource Identifier (URI), which is a universal reference system for online resources, such as documents and hypertext images. The URI, usually called a URL, is defined by RFC 3986 ↓.
  • HTTP protocol, specifically RFC 2616 ↓ and RFC 2617 ↓, which determine how the browser and server authenticate[[[[take note].

Access to the WWW is possible for everyone, regardless of whether the user is a completely disabled person. Regardless of the type of disability, the Web aims to transmit, obtain information and interact with society, making it extremely important to allow access to the network for people with disabilities, usually with reduced mobility. Tim Berners-Lee says that “the power of the internet is in its universality. Accessibility for everyone, regardless of disability, is its main aspect”. Many countries require website authors to use accessibility. International agreements under the W3 Consortium Web Accessibility Initiative (Web Accessibility Initiative) led to some simple guidelines that web content authors and software developers can use to enable people with disabilities to “browse” the web[[[[take note].

Different language support[[[[To edit | edit code]

W3C ensures that the web service is available in all languages ​​in the world. In early 2004 Unicode gained considerable popularity and, in December 2007, as the most widely used character encoding system on the Web, it replaced ASCIIas well as the character set for Western Europe. Originally a collection RFC 3986 ↓ allowed network objects are identified only by addresses that consist of characters from the US-ASCII subgroup. RFC 3987 ↓ recognizes the extended character range and from now on network resources can be identified by addressing each language[[[[take note].

The overload of the Internet infrastructure, caused by the predominance of demand over supply, generally causes significant delays in browsing websites. There was even a humorous term for the world: “World Wide Wait” (which means “big world waiting”). The acceleration of network operation is still an open topic for discussion and reflection by users, experts and the field of technology QoS. Other solutions to speed up the Internet can be found at the W3C[4].

The standard guidelines for optimal server response time are[[[[take note]:

  • 0.1 seconds (one tenth of a second) – ideal response time. The user is not delayed.
  • 1 second – maximum response time allowed. A response time of more than 1 second interrupts the user’s work.
  • 10 seconds – unacceptable reaction time. Navigation will stop and the user will likely see an error message.

According to a 2001 survey, there were more than 550 billion documents on the Internet, most often available on the so-called “visible WWW” (ang. Visible web or Surface web), that is, cataloged (indexed) by Internet search engines or the so-called “hidden web” Hidden Web or deep web), that is, not cataloged by search engines. In 2002, the content of 2.024 billion sites was tested, thanks to which it is known that, by far, the largest content on the Web was in English: 56.4%; next, pages in German (7.7%), French (5.6%) and Japanese (4.9%). Recent searches have used web search engines in 75 different languages ​​to collect samples from websites. It was established that, as of the end of January 2005, there were more than 11.5 billion publicly indexed sites. There were already at least 25.21 billion pages in March 2009. July 25, 2008 software engineers Google Jesse Alpert and Nissan Hajaj announced that the search engine has discovered a billion unique URLs. Of the 109.5 million domains in operation in May 2009, 74% were commercial (that is, sites operating on top level domain .with)[[[[take note].


Paula Fonseca