As I understand it, the Gulags were the worst prison in the Soviet Union, dedicated to prisoners who the state felt committed crimes of political nature (and I’d imagine other crimes as well)
What actually happened to the Gulag once the Soviet Union collapsed?
Was it shut down? Were prisoners released? Does it still exist in some form today?
If it does still exist, who gets sent there, and how does it compare to what it was like during the soviet era?
Not to discourage further answers, but you might want to check out this answer I wrote about what happened to Soviet prisoners at the dissolution of the USSR.
Specifically - by late 1991 there were only 40 political prisoners and 30 "prisoners of conscience" left in Soviet prisons, mostly at Perm-35 camp. The last were pardoned in early 1992.