Search engines that use other search engines are called

Search engines that use other search engines are known as meta search engines.

When we browse on a meta search engine, it uses information from other big engines like google, bing etc and show at the results of input.

It take advantage of indexes created by other search engines.

Examples of famous meta search engines are:

Yandex. IxQuick. Dogpile.

The awnser meta search engine