Web Crawlers are automated scripts that browse the web and collect data. They systematically visit web pages, following links and extracting information to build an index or gather specific data. Web crawlers are essential for search engines, data mining, and web scraping applications. They can operate continuously, keeping the collected data up-to-date by revisiting sites periodically. Web crawlers need to be carefully configured to respect robots.txt files and avoid overloading websites with excessive requests. They are foundational tools for exploring the vast amount of information available on the internet.