The increasing number of the Web data due to the increased amount of the digitalized standards, electronic mails, images, multimedia, and Web services, the World Wide Web rises as the cost-effective resource for releasing the data and for discovering the knowledge. Thus, the open challenges for the information retrieval efforts have received much attention among the researchers to deem the browsing as an appropriate searching procedure. To facilitate the most relevant information, it is necessary to develop a unique and extensive structural framework that offers a platter and a navigational proxy to the clients and servers. Consequently, the search engines play a vital role in contributing the users in providing the related Web pages from the Web. A Metasearch engine, in essence, is a search mechanism that sends the user query to a number of modern search engines autonomously and provides the combined outcome through their own unique page ranking technique. This chapter intends to discuss the necessity of metasearch engines, starting with a series of definitions of search engines and its classification. Further, a summary of metasearch engine is provided with the architecture and the result-merging methods. It also states several criteria that validate the stability of metasearch engines and, finally, conclude the chapter explaining the future work.