How Browsers Work ?

The browser's main components are :

1. The user interface - this includes the address bar, back/forward button, bookmarking menu etc. Every part of
the browser display except the main window where you see the requested page.
2. The browser engine - the interface for querying and manipulating the rendering engine.
3. The rendering engine - responsible for displaying the requested content. For example if the requested content
is HTML, it is responsible for parsing the HTML and CSS and displaying the parsed content on the screen.
4. Networking - used for network calls, like HTTP requests. It has platform independent interface and underneath
implementations for each platform.
5. UI backend - used for drawing basic widgets like combo boxes and windows. It exposes a generic interface
that is not platform specific. Underneath it uses the operating system user interface methods.
6. JavaScript interpreter. Used to parse and execute the JavaScript code.
7. Data storage. This is a persistence layer. The browser needs to save all sorts of data on the hard disk, for
examples, cookies. The new HTML specification (HTML5) defines 'web database' which is a complete
(although light) database in the browser.

Conceprual diagram of a main browser components: