With the rapid development of new technologies, the application of recommendation engines is becoming more and more popular. For example, Spotify (music platform), Netflix (video platform), Facebook (social media platform), and Amazon (e-commerce website) are well-known examples of massively adopting recommendation engines. A recommendation engine is a machine learning technology that can predict a user's preference for a specific product. The leading technologies used in the recommendation engines include collaborative filtering, content-based filtering, and association analysis.

        Association analysis is to evaluate the association between the two items. Collaborative filtering recommends the same products to similar users based on consumers' ratings and consumption habits. Content-based filtering is based on the similarity calculation of product attributes.