What is this on youtube!

so on a few songs i see that they have
"Licensed to YouTube by" then a few tags i was wondering what is this and how do you get it?

https://imgur.com/VSNcDZ4

It means the author has allowed their song to be posted on YT.

Ads show up and all the money from ads goes to the author (unless they allowed revenue sharing). The field in the description simply tells the viewer the name of the song.