What does "covering a song" mean?

When someone takes a song, and sings it. Let's say Akon sang Thriller. That would be a cover because it was originally by Michael Jackson.

It's when someone else (as in not the original artist) sings the song. For example if you type in Adele covers on youtube you will get tons of hits of OTHER people singing her songs and not Adele herself.

I consider it as making a disc as competition to the original. If it's made a good time later,I consider it a remake.

The term cover,now seems to refer to anyone who has made a recording of a song,no matter how old it it is

Performing a song someone else did