" Even at that early date, the basic building blocks of web search had been already set in stone. Search was a four-step process. First came a sweeping scan of all the world’s web pages, via a spider. Second was indexing the information drawn from the spider’s crawl and storing the data on racks of computers known as servers. The third step, triggered by a user’s request, identified the pages that seemed best suited to answer that query. That result was known as search quality. The final step involved formatting and delivering the results to the user. "

― Steven Levy , In the Plex: How Google Thinks, Works, and Shapes Our Lives