What is a search engine?

A search engine is a program that provides relevant results from the Internet for users' search queries and lists them according to a specific ranking. The search results consist of data from other websites and the ranking is determined by the search engine's algorithm.

Google is probably the best-known search engine. Some alternatives to Google are, for example, the search engines Bing, Baidu, DuckDuckGo or Yandex. Like Google, all of these search engines have both a web crawler and their own index.

There are also other types of search engines. For example, there are special search engines that are only intended for children, meta search engines, proxy search engines or search engines for hidden services.

In the online marketing sector, various aspects, such as meta data or website content, can be optimized for search engines (SEO) in order to increase the ranking of a website.