Collaborative filtering (CF) is one of the most popular techniques for building recommender systems. It is a method of making automatic predictions about the interests of a user by collecting preferences or taste information from many users (collaborating).
Recommender systems have become ubiquitous and very important in recent years. They are present in a variety of areas, such as for recommending movies, music, news, books. One of the most popular algorithms used to produce a list of recommendations is collaborative filtering.