If an item in the catalog is marked as Loanable, that means you're allowed to borrow it. Most books are loanable, except reference books and a few other special cases. 

If the item’s location says something about Reference, Periodicals, Non-Circulating, or Reserves, you can only use it inside the library, and you cannot request that it be sent to a different campus.

If an item in the catalog is marked as In Place, it should be available on the shelf and checked out or requested. 

If an item in the catalog is marked as On Loan, someone has already checked out this item. It should not be on the shelf. You should request a different copy through GIL-Express or Interlibrary Loan.

For more help, ask a librarian.