What are the major components of a modern web browser?

A browser is a software application used to locate, retrieve and display content on the World Wide Web, including Web pages, images, video and other files. As a client/server model, the browser is the client run on a computer that contacts the Web server and requests information. The Web server sends the information back to the Web browser which displays the results on the computer or other Internet-enabled device that supports a browser.

Primary components of a browser are

1. User Interface – This consists of forward and back button, bookmarks, address bar etc. along with the window that displays the requested page.
2. Browser engine – It commands action between rendering engine and the user interface.
3. Rendering engine – The main function of rendering engine is to display the content that is requested. For example, if an HTML content is requested, the engine parses CSS and HTML and when the content is parsed, it is displayed on the screen.

Since all browsers have different underlying rendering engine, the way which they render a website or webpage is completely different. That’s why you might sometimes face incompatibility issues with some browsers. Hence, you need to test your website across all browsers in order to provide a seamless experience to all your users. In such a case, a tool like LambdaTest can be of utmost use to help you test your website across all different browsers and browser versions. You can test and debug your website across thousands of browser combinations.

1. User Interface backend – It can be used for painting basic images like windows or combo box. The backend exposes only a generic platform independent interface. Beneath it, user interface methods are used by the operating system.
2. JS Interpreter – JavaScript and all other types of scripting is parsed and executed by the inbuilt interpreter.
3. Networking – Performs implements of HTTP request and response.
4. Data Storage – All types of data, like cookies are saved locally by the browser. Storage mechanisms like WebSQL, FileSystem, localStorage are also supported by the browser.