Basically a Web search engine have four software modules in the index. We know the detail of this implied program architecture. The Crawling module provide updated or new pages to the Indexing unit. The Indexing unit creates a searchable index that contain pre-processed background information for page ranking. The module of searching, using index, an answer is found that is categorize on a stream of queries from users. Finally, answering module creates to the answer page and places the correct ad related to a query.