Indexing the Web—It’s Not Just Google’s Business
Web databases do much more than passively store information. Part of their power comes from indexing records efficiently. An index serves as a map, identifying the precise location of a small piece of data in a much larger pile. For example, when I search for “web development,” Google identifies two hundred million results and displays the first ten—in a quarter of a second. But Google isn’t loading every one of those pages and scanning their contents when I perform my search: they’ve analyzed the pages ahead of time and matched my search terms against an index that only references the original content.
Mullican, Lyle. List Apart, A (2009). Articles>Web Design>Information Design>Search Engine Optimization