What is Cheerio? What are the differences between Cheerio and jQuery?

Cheerio is a fast, flexible, and powerful HTML parser based on Node.js that implements jQuery's core API but is designed specifically for server-side environments. Unlike jQuery in the browser, Cheerio doesn't render DOM, doesn't process CSS styles, and doesn't execute JavaScript, making it extremely lightweight and efficient.

Key features of Cheerio include:

1. Lightweight: Core code is only a few hundred lines with excellent performance
2. jQuery Syntax: Uses familiar jQuery selectors and manipulation methods
3. Server-side: Runs in Node.js environment without browser dependencies
4. Fast Parsing: Uses htmlparser2 as the underlying parser for fast parsing
5. Flexible: Supports various HTML/XML parsing options

Typical use cases for Cheerio include web scraping, data extraction, and HTML content processing. It can extract data from HTML strings or files, modify DOM structure, and generate new HTML content.

Basic usage example:

javascript
const cheerio = require('cheerio');
const $ = cheerio.load('<div class="container"><p>Hello World</p></div>');

// Use jQuery selectors
$('p').text(); // 'Hello World'
$('.container').html(); // '<p>Hello World</p>'

// Modify DOM
$('p').addClass('highlight').text('Updated Text');

Cheerio is suitable for processing static HTML content. If you need to handle dynamically rendered pages (requiring JavaScript execution), you should combine it with tools like Puppeteer or Playwright.