A playlist is a custom compilation of songs and music videos. You might want to create a playlist to do the following:
Suit a specific mood or occasion. For example, you could create a playlist for a dinner party, a wedding, or your morning workout.
Select certain songs to share with others on your local network or to sync with your Mac or Windows device.
Organize your music library.
When you How to get your Apple Music Replay.
Collaborative playlists: See Adjust the sound in Music on iPad