1 A search engine is a program or application used to search content of any kind for a specific search term. After the search query, the search results are usually presented in a list of links. Search engines exist online, which can be called up in the browser as a stand-alone website, e.g. Google, DuckDuckGo, Ecosia, integrated into websites as well as locally in programs or other offline applications.
The three essential tasks of a search engine are: Searching & indexing of content as well as index maintenance (on the web with the help of crawlers) Process search queries & find hits by a specific search algorithm Prepare & present results for the searcher