HAPPY MODEL SCHOOL Computer Application (Code: 165) Class : X Rajesh Singh (9235838393) Day-2 : 06.05.2020

WORLD WIDE WEB (WWW)

English scientist Tim Berners-Lee invented the in 1989. The World Wide Web (WWW), commonly known as the Web, is an information system where documents and other web resources are identified by Uniform Resource Locators (URLs, such as ://www.example.com/), which may be interlinked by hypertext, and are accessible over the . The resources of the WWW are transferred via the Hypertext Transfer Protocol (HTTP) and may be accessed by users by a software application called a and are published by a software application called a web server.

The terms Internet and World Wide Web are often used without much distinction. However, the two terms do not mean the same thing. The Internet is a global system of interconnected computer networks. In contrast, the World Wide Web is a global collection of documents and other resources, linked by hyperlinks and URIs. Web resources are accessed using HTTP or HTTPS, which are application-level Internet protocols that use the Internet's transport protocols.

Web server

A "Web server" can refer to hardware or software, or both of them working together.

1. On the hardware side, a web server is a computer that stores web server software and a website's component files (e.g. HTML documents, images, CSS stylesheets, and JavaScript files). It is connected to the Internet and supports physical data interchange with other devices connected to the web. 2. On the software side, a web server includes several parts that control how web users access hosted files, at minimum an HTTP server. An HTTP server is a piece of software that understands URLs (web addresses) and HTTP (the protocol your browser uses to view webpages). It can be accessed through the domain names (like mozilla.org) of websites it stores, and delivers their content to the end-user's device.

At the most basic level, whenever a browser needs a file which is hosted on a web server, the browser requests the file via HTTP. When the request reaches the correct web server (hardware), the HTTP server (software) accepts request, finds the requested document (if it doesn't then a 404 response is returned), and sends it back to the browser, also through HTTP.

Some commonly known web server:

1. Apache 2. Microsoft's Internet Information Server (IIS)

3. Nginx (pronounced engine X)

4. Novell's NetWare server 5. Google Web Server (GWS)

6. IBM's family of Domino servers.

Web Client and Web browser

A web client is an application that communicates with a web server, using Hypertext Transfer Protocol (HTTP). Hypertext Transfer Protocol is the protocol behind the World Wide Web. With every web transaction, HTTP is invoked.

Web browser is an example of a web client.

A web browser (commonly referred to as a browser) is a software application for accessing information on the World Wide Web. When a user requests a particular website, the web browser retrieves the necessary content from a web server and then displays the resulting web page on the user's device (Computer, Laptop, Mobile etc.).

A web browser is not the same thing as a search engine, though the two are often confused. For a user, a search engine is just a website, such as Google Search, Bing, or DuckDuckGo, that stores searchable data about other websites. However, to connect to a website's server and display its web pages, a user must have a web browser installed.

The first web browser, called WorldWideWeb, was created in 1990 by Sir Tim Berners-Lee. 1993 was a landmark year with the release of , credited as "the world's first popular browser". Its innovative graphical interface made the World Wide Web system easy to use and thus more accessible to the average person.

Some most commonly used web browsers: 1. 2. Mozilla 3. 4. 5. 6.