Browser components

A browser consists of several key components that work together to render web pages and execute JavaScript.

Rendering Engine

• Parses HTML and CSS to build the DOM and CSSOM trees.
• Combines them into a render tree and paints pixels to the screen.
• Examples: Blink (Chrome, Edge), Gecko (Firefox), WebKit (Safari).

JavaScript Engine

• Executes JavaScript code.
• Handles compilation, optimization, and garbage collection.
• Examples: V8 (Chrome, Node.js), SpiderMonkey (Firefox), JavaScriptCore (Safari).

Browser APIs

• DOM API — manipulate HTML elements.
• Fetch API — make HTTP requests.
• Storage APIs — localStorage, sessionStorage, IndexedDB.
• Web APIs — Geolocation, WebRTC, Canvas, WebGL.

Network Stack

• Handles HTTP/HTTPS requests.
• Manages DNS resolution, TCP connections, TLS handshakes.
• Implements caching and cookie management.

UI Components

• Address bar, navigation buttons, bookmarks, developer tools.
• Tab management and window controls.

Security Features

• Same-origin policy enforcement.
• CORS handling.
• Content Security Policy (CSP) support.
• Sandboxing for untrusted content.