The aim of proposed systems (also called as collaborative filtering systems) is to suggest items which a client is expected to order. In this paper we describe the recommendation system related research and then Introduces various techniques and approaches used by the recommender system User-based approach, Item based approach, Hybrid recommendation approaches and related research in the recommender system.  Normally, recommended systems are used online to propose items that users discover interesting, thereby, benefiting both the user and merchant Recommender systems benefit the user by building him suggestions on things that he is probable to buy and the business by raise of sales. we also explained the challenges, issues in data mining and how to build a recommendation system to improve performance accuracy by applying the techniques.