Crawling protocols are rules that guide web crawlers, which are automated programs used by search engines like Google to discover and index content on the internet. These protocols help crawlers understand which pages to visit and which to ignore, ensuring efficient use of resources and preventing overload on web servers. One common crawling protocol is the Robots.txt file, which website owners can use to communicate with crawlers. This file specifies which parts of a site can be accessed by crawlers and which should be excluded, allowing for better control over how content is indexed and displayed in search results.