Usually website which using software robots to harvest all informations on Internet. This informations are presented in a list. Users are using keywords to search for informations in list. For website owners and webmasters is especially important position in list on choosen keywords. In example: if you are selling shoes in Aberdeen, is important, if you are first or on seventeenth on "shoes aberdeen" keyword. All customers, who are using this search engine, will see first position, only few will browse down to seventeenth... Way how to go up in list are called SEO optimisation.

Most known Web search engines: Google, Altavista, Yahoo, Bing.

Misspellings: Gogle, Goole, Googl, Astalavista, Yaho, Searching engine