A search engine is a computer program that retrieves documents or files or data from a database or from a computer network (especially from the internet)
wikipedia said:Though the numbers are not publicly known, some people estimate that Google maintains over 450,000 servers, arranged in racks located in clusters in cities around the world, with major centers in Mountain View, California; Council Bluffs, Iowa; Herndon, Virginia; Lenoir, North Carolina; Atlanta, Georgia; Dublin, Ireland; Saint-Ghislain, Belgium; Zürich, Switzerland; Tokyo, Japan; Beijing, China;[1][2] and new facilities constructed in The Dalles, Oregon.[3]