HOW A WEB BROWSER WORKS??

Well, you  reading this article shows you are using web browser, presenting this article content in a rich text/graphical format on your screen. A web browser  is an application software that  provides access to the World Wide Web. It fetches the web pages from the server along with the necessary files like, images, flashes, videos etc, interprets them and then displays it on the screen. On  simply typing the URL (Uniform Resource Locator) of a webpage in the address bar , the browser will bring the web page on your screen.Initially, user inputs a Uniform Resource Locator (URL), for example http://www.fb.com/, into the browser. The prefix of the URL, the Uniform Resource Identifier or URI, determines how the URL will be interpreted. The most commonly used kind of URI starts with http: and identifies a resource to be retrieved over the Hypertext Transfer Protocol (HTTP).Other prefixes are https: for HTTPS, ftp: for the File Transfer Protocol, and file: for local files. Prefixes that the web browser cannot directly handle are often handed off to another application entirely. For example, mailto: URIs are usually passed to the user's default e-mail application, and news: URIs are passed to the user's default newsgroup reader.
In the case of http, https, file, and others, once the resource has been retrieved the web browser will display it. HTML and associated content (image files, formatting information such as CSS, etc.) is passed to the browser's layout engine to be transformed from markup to an interactive document, a process known as "rendering".  Most browsers can display images, audio, video, and XML files, and have plug-ins to support Flash applications and Java applets. Upon encountering a file  that is set up to be downloaded rather than displayed, the browser prompts the user to save the file to disk.
Each link contains the URI of a resource to go to. When a link is clicked, the browser navigates to the resource indicated by the link's target URI, and the process  begins again.

1.      User Interface – It is the space where interaction between users and the browser occurs.eg - an address bar, next and back buttons, buttons for home, refresh and stop, options to bookmark web pages, etc.
2.      Browser Engine – It is the  code that communicates the inputs of user interface with the rendering engine. It is responsible for querying and manipulating the rendering engine according to the inputs from various user interfaces.
3.      Rendering Engine – It is the part  responsible for displaying the requested content on the screen. It first parses the html tags and then using the styles, it builds a render tree and finally a render layout, which displays the content on the screen.
4.      Networking – The  code , responsible to send various network calls.eg- sending the http requests to the server.
5.      Java Script Interpreter – It is the component  to interpret the java script code .
6.      UI Backend – This draws basic widgets on the browser like combo boxes, windows, etc.
7.      Data Storage – It is small database created on the local drive of the computer where the browser is installed. This database stores various files like cache, cookies, etc.

Browsers which include additional components to support e-mail, Usenet news, and Internet Relay Chat (IRC), are  referred to as "Internet suites" .
All major web browsers allow the user to open multiple information resources at the same time, either in different browser windows or in different tabs of the same window. Major browsers also include pop-up blockers to prevent unwanted windows from "popping up" without the user's consent.
Most web browsers can display a list of web pages that the user has bookmarked so that the user can quickly return to them.