What Are Search Engines

A search engine is a program to help find information that is stored in a computer or a computer network such as the World Wide Web.  Internet search engines have their origins in information retrieval systems.

After entering a search query a search engine returns a list of references to potentially relevant documents, usually depicted with a title and a brief excerpt of the document. Various search methods can be applied.

The major elements or tasks of a search engine are:  Creation and maintenance of an index (data structure with information about documents); processing of search queries (finding and sorting of results) and processing of the results in the most meaningful form.  In general, the data collection is done automatically by the web crawler on a single computer by regularly reading all the files in directories specified by the user’s local file system.

Search engines can be categorized according to a number of characteristics. The following characteristics are largely independent. You can choose to design a search engine, which proposed the possibility of each of the groups of characteristics, without affecting the choice of other characteristics.