Imagine that you are running a website that allows users to listen to their favorite songs. To make it easier for them to manage their music library, users can tag songs with whatever tags make sense to them. You will end up with a lot of tracks tagged with rock, hiphop, and electronica, but also with some tracks tagged with my_16th_birthday_favorite_anthem.사용자들이 각자가 좋아하는 노래를 들을 수 있는 website를 운영..