Weighting scheme for ordering results Other features, such as cached pages Directories index sites according to categories. There are few pure search engines nowadays. Most have some directory features. Search Syntax A search word or combination of words connected with operators is called a query . The rules, or syntax , for forming a query vary from one search engine to another.
Some search engines have only a few simple ways to search.
Others are very powerful and allow complicated queries with all kinds of special operators, truncation, and special searches. Many aspects of this find are controversial.