A "crawler" is a type of software program used by search engines like Google to explore and index content on the internet. It systematically navigates web pages by following links, gathering information about the content, and storing it in a database. This process helps search engines provide relevant results when users enter queries. These crawlers are also known as "spiders" or "bots." They play a crucial role in maintaining up-to-date search results by regularly revisiting websites to check for new or changed content. This ensures that users receive the most accurate information available online.