That depends. Usually a rental means you got it from the Bookstore, but sometimes people get confused between that and the library because we both loan out books.
Yes, that's pretty darn close together! Here is a map to help out:
If you get confused and put it in the wrong one, it will probably be okay because we usually end up doing a big old book swap at the end of each semester where we give them all the rental books that got returned to us and they give us all the library books that got returned to them. This may delay the time it takes to get checked in to the right place so if your item might be marked as late by the time it gets to it's proper home, with whatever consequences that may entail.