Googlebot is Google’s web crawling bot (sometimes also called a “spider”).

Crawling is the process by which Googlebot discovers new and updated pages to be added to the Google index. We use a huge set of computers to fetch (or “crawl”) billions of pages on the web.

Googlebot, a web crawler that finds and fetches web pages.

The indexer that sorts every word on every page and stores the resulting index of words in a huge database.

The query processor, which compares your search query to the index and recommends the documents that it considers most relevant.