The meaning of “Remastered”


A lot of music I already have is being re-released and “remastered”.  Some of those contain new tunes or printed material and I might buy (again) just to have that.  Otherwise, what’s the value of a new master?  I remember direct to disc vinyl was said to be limited to 10,000 copies because the “master” from which copies were pressed, wore out.  Tape masters would have physically limited lifespans, too.  But in the age of digital music, what is a remaster?  I suppose a new release could have been “re-mixed” or “re-normalized”, so there may be real sonic differences which may or may not be an improvement.  Does the use of the term mean there is some actual audible voodoo by an engineer rather than just procreation of an existing audio file?
77jovian
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?
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.