Recommendation system is kind of information filtering system,suggesting relevant items to users. Recommendation systems are widely used on the Web for recommending products and services to users. Many e-commerce sites have such systems. Collaborative filtering is an important technology for recommender systems. Users are interested in grouping items into categories and for each category; there can be corresponding user group who like items in that category. Finding interest of user in particular item group and grouping users of similar interest is distinguishable feature, which differentiate this work. This system mentioned in book can overcome several limitations of traditional algorithms.