The meaning of “Remastered”

Thanks for the responses.  So, there's no standard use of the term.  Remaster could just be another generation of the original recordings with no attempt to change the sound or, on the other hand, a completely new artistic vision, which I would think of more as a remix.  Or maybe just a compressed version designed to sound louder.  But likely there will be some sonic change.  Often, just to tempt us to buy the music again.

I know lots of people have their favorite versions of various albums, but is there a resource that tracks the versions and comments on what changes have been made?

remastered=buyers remorse.

Some "remastered" CDs sound cleaner and better, some worse.  It is possible that they removed noise or digitized again with stable A/D clock.  Artifacts of jittery A/D conversion cannot be removed ever.  The only option is to digitize (remaster) again, if analog tapes still exist.  I've heard stories of early digital recordings made from analog tapes already frequency corrected for vinyl pressing, resulting in bright unpleasant sound.

Before CD’s or DSD’s or LPs are cut a final master is made. This final master may go back to a previous 2 track master or to multi-track originals.

Re-mastering means that a new final master was made and that the new mastering engineer has re-thought something. EQ, compression or the down mix from the original multi-track are quite common.

Really depends on who is doing the remaster and how good the material was they had to start with.

It was also true that some DSD's were remastered compared to the CD's, and they had different frequency profiles and compression profiles, leading to the obvious conclusion they sounded different.

I know lots of people have their favorite versions of various albums, but is there a resource that tracks the versions and comments on what changes have been made?

I don’t think there’s a simple way to find the best versions of particular albums. No list of the best anywhere. If you want to read discussions of what is the best version of a CD or LP, check out the Steve Hoffman Music Forums.  Steve is a mastering engineer, so you can find discussions of what that means too.
https://forums.stevehoffman.tv/forums/music-corner.2/

You’ll find all kinds of music discussions there and people who give new meaning to the word obsessed. The discussions about albums you’re interested in may have taken place years ago, so you’ll have to get good at searching the forum. They also have classified ad forums, so you may be able to buy some of the better versions there.
https://forums.stevehoffman.tv/

If you want to find which CD or LP releases are more compressed or which have greater dynamic range (less compressed), check out the dynamic range database.
http://dr.loudness-war.info/

Take a look at those sites and if you have any questions, let us know.