What does a web browser
Sir Tim Berners-Lee
In the contemporary society, with the various technological
influences, even a three year old kid would know the term “Web
Browser.”Due to the fact that internet is pretty closed to many
families, children know that they need a web browser to surf internet.
But most of them and also most of the general public are not aware of
the functions of a web browser beyond the fact that it shows us web
pages that are requested by us. This article will give a simple overview
of web browsers. But please note that there are many complex aspects web
browsers when it comes to completing its main objectives.
Web browser is a software application that enables retrieving,
presenting and traversing information in the internet as well as in web
servers that host web based software applications via private networks.
These browsers are sometime called as clients as they act a client or
interface between the user (you and me) and backend (server side).
Famous web browsers are:
* Internet Explorer for Windows
* Safari for Mac
* Opera, Google Chrome and Mozilla Firefox for many platforms and
also there are many others too....
The very first web browser was created by Sir Tim Berners-Lee in
1990. It was then called Worldwide Web and later renamed Nexus. In 1993,
web browser technology was innovated by Marc Andreessen with the release
of Mosaic (later Netscape), “the world’s first popular browser,”which
made the World Wide Web system easy to use and more accessible to the
average person. Andreessen’s browser sparked the internet boom of the
1990s but the introduction of Mosaic in 1993 allowed the world to
experience one of the first graphical web browsers which led to an
explosion in web use (Reference/Source: Wikipedia)
Function in brief:
A web browser preliminary knows the language, i.e. HTTP (Hyper Text
Transfer Protocol). That means a web browser sends and retrieves data
(communicate) by using the above protocol. Most of the modern browsers
know protocols like HTTPS (Hyper Text Transfer Protocol Secure), FTP
(File Transfer Protocol).
Objectives of a browser in a nutshell:
- Retrieval of information upon the request by the user
- Rendering the information retrieved. (Allow the users to view the
- Access other information (When users clicks on other links)
So, the function starts with user giving the needed URL. What is a
URL? It stands for Uniform Resource Locator, which is most commonly
known as the web address.
Example URL is
* The prefix of the URL or the first set of strings stands before the
colon mark (:), is called the Uniform Resource Identifier or URI, that
determines how the URL will be interpreted i.e. what is the protocol
that should be used for communication (when it comes to the term
communication, a web browser always act as communication interface
between the user and the server which are located in two different
places, So this communication is called the client-server
communication). In the above example, it is Hypertext Transfer Protocol
(HTTP) which is the most common protocol.
* Browser will send the request to the relevant server which host the
web page and then retrieve it. If it is a LAN (Local Area Network) of an
organization or institution then most probably they have proxy server
before their network is exposed to the outer world (i.e. Internet), So,
in those cases the request sent by the browser is accepted by the proxy
server (which should be already configured in the browser) and if the
proxy server has the particular web page in its cache then it shows it.
* So, after having retrieved the information (which are HTML - Hyper
Text Markup Language) and other associated content (image files,
formatting information such as CSS, etc.), those information are sent to
the browser’s layout engine (which is in-built with the browser) to
transform them into a readable and visible information. This process is
What is a web browser engine? (or layout engine/rendering engine)
A web browser engine, is a software implementation (normally built-in
with the browser) which absorbs marked up content (e.g. HTML, XML, image
files, etc.) and formatting information (e.g. CSS, XSL, etc.) and
displays the formatted content where the user can read and visualise the
information in a lucid and palatable way.
This engine is embedded not only in web browsers but also in e-mail
clients, e-book readers or other applications that need the displaying
(and editing) of web content. Typically engines may wait till all data
are received before rendering a page, or may begin rendering before all
data is received. That differs with the engine design technology.
Browser engines of famous web browsers:
Trident - Microsoft Internet Explorer
Gecko - Mozilla Firefox
Presto - Opera