What is the difference between my library and playlist?

[user-removed]

When I joined I spent hours choosing my playlist or my songs let's put it that way. When I finally got in I found the songs were in something called a library not my playlist. What is the difference between the two?

[phan_times]

So your library is filled with all the songs you enjoy. Playlists can have specific songs if you are going for a certain mood. You can have multiple playlists, but only have one library. Most people usually make playlists. You can also rename playlists and have people follow your playlists. You can not do either of these with your library. 

[user-removed]

Can use both the library and playlist offline. Want something I can listen
to when I'm on an airplane

[phan_times]

Yeah as long as the music is downloaded.