If The Rolling Stones are a "glorified cover band", they certainly are a rich, successful "glorified cover band".

They are the same, but different. Both are cover bands, because they "cover" songs by other artists. A tribute band usually covers other artists' material, but they focus on a particular group or era. So, a tribute band is more focused than an average cover band.

The word "cover band" refers to the thoughtful image one gets when they see or listen to a particular band. This cover can be a bad or good image, the choice is decided on the public opinion.

A band that plays (covers) other artists music.

It's a good idea for a band to do a cover because if the song is very popular with people it gain the band tends to gain more followers/fans.