A search engine or search
service is a program designed to help find information stored on a
computer system such as the World Wide Web, inside a corporate or
proprietary network or a personal computer. The search engine allows one
to ask for content meeting specific criteria (typically those containing
a given word or phrase) and retrieves a list of references that match
those criteria.
Search engines
use regularly updated indexes to
operate quickly and efficiently. Without further qualification,
search engines usually refers to a Web search engine, which
searches for information on the public Web. Other kinds of search engine
are enterprise search engines, which search on intranets, personal
search engines, which search individual personal computers, and mobile
search engines. However, while different selection and relevance
criteria may apply in different environments, the user will probably
perceive little difference between operations in these.
Google search is the world's most popular search engine. Some
search engines also mine data available in newsgroups, large
databases, or open directories like DMOZ.org. Unlike Web directories,
which are maintained by human editors, search engines operate
algorithmically. Most websites which call themselves search engines are
actually front ends to search engines owned by other companies. |
