A web browser is an application software that allows users to access and view information on the World Wide Web¹. A web browser acts as an interface between the client and the server, and requests web documents and services from the server using HTTP protocol¹.

The basic architecture of a web browser consists of the following components³:

• Controller/Dispatcher: This component works as a control unit that takes input from the keyboard or mouse, interprets it, and makes other services work on the basis of the input. For example, when a user enters a URL in the address bar, the controller sends a request to the server for the web page associated with that URL.

• Interpreter: This component receives the information from the controller and executes the instructions line by line. Some interpreters are mandatory while some are optional. For example, HTML interpreter is mandatory to render the web page, while JavaScript interpreter is optional to execute the scripts embedded in the web page.

• Client Programs: These are the programs that provide additional functionality to the web browser, such as displaying images, playing audio or video, or running plug-ins or extensions. For example, a web browser may use an image viewer program to display JPEG or PNG images, or a media player program to play MP3 or MP4 files.

The architecture of a web browser may vary depending on the implementation and design choices of different vendors. However, most modern web browsers follow a similar structure that consists of the following layers²: