What is the definition of "meta search engine"?

A meta search engine is a search engine that searches other search engines and databases to provide a variety of results. It gives the user the ability to enter a search once and receive results from multiple sources.

A meta search engine uses a complex algorithm to search a variety of online databases and compiles a list of sites containing the keywords provided by the user. Even though the user saves time by receiving results from multiple search engines, a meta search engine may not always provide the best results. Unlike using an individual search engine, there is a higher chance that the results include irrelevant sites that do not match the initial inquiry.