Indexing: Google analyzes the text, images, and video files on the page, and stores the information in the Google index, which is a large database. Serving search results: When a user searches on Google, Google returns information that's relevant to the user's query.

When a search query is entered into a search engine by a user, all of the pages which are deemed to be relevant are identified from the index and an algorithm is used to hierarchically rank the relevant pages into a set of results. The algorithms used to rank the most relevant results differ for each search engine.

It's the means by which data is organized and structured so that search engines can generate relevant search results. Search indexing can transform any and all data and file types into searchable data. The goal is to make searching as fast, accurate, and relevant as possible.