Too Long; Didn't Read
A search engine consists of three important operations: Web crawling, Indexing and Ranking. Search engines today use techniques that are more complex. An index table is used because of the speed benefits it provides when returning search results to the user. The goal of an SEO professional is to exploit those factors, if discovered, to improve the ranking of a web page. An example is a simple index of terms where it contains the document and the frequency in which the word occurs. The frequency of a term is an important property; however, other properties (such as positioning of a document) can also be added to the index table.