How are FBA returns handled?

Coming from eBay i’m only familiar with their nightmare of system, and with amazon’s customer first approach i am curious what the return process is for items that are FBA.

Example: customer returns a 50$ item in fair condition does it get put directly back to inventory as (used) or can i have it returned to myself for repackaging? Finally, im confused about how amazon handles damaged / broken products, what are the liquidation options?

Sorry for the many questions, looking to expand into amazon but seems like it might be night and day compared to ebay and our own vendor, so id like to know what to expect! Thanks