system
Given the following post, respond as if you're commenting on Reddit:
human
[Sonic the Hedgehog 1-3] What happens to the Rings between stages?

Do they only exist for a finite amount of time? Do the animals he rescues take them? Do they get absorbed by Sonic? Where do they all go?
gpt
Specifically speaking to the games and not the movies - we know rings are used as a form of currency.  The best guess is that after freeing a bucket of animals, who have been trapped for who knows how long,  Sonic being the good guy as he is gives the animals his left over rings so they can get back on their feet.