Web scraping extracts data from websites for analysis and automation. parses HTML and XML documents with Python. Install with pip install beautifulsoup4 and requests. Navigate parse trees using find(), find_all(), and CSS selectors. Extract text with .get_text() and attributes with bracket notation. Handle different encodings and malformed HTML gracefully. Selenium automates browsers for JavaScript-heavy websites. Use with ChromeDriver or GeckoDriver for Firefox. Wait for elements using explicit waits with expected conditions. Handle dynamic content loaded via AJAX requests. Scrolling, clicking, and form filling are automated with Selenium. Respect robots.txt and website terms of service. Implement rate limiting with time.sleep() between requests. Rotate user agents to avoid detection. Use proxies for large-scale scraping. Store scraped data in CSV, JSON, or databases. Handle errors gracefully with try-except blocks. Use Scrapy framework for large-scale scraping projects. Ethical scraping respects server resources and copyright. Always check the legality of scraping specific websites.