the bank has the legal right to increase the money supply AKA 'print money' so to give you a $100 loan the bank can just create those $100 and give give them to you pretty neat arrangement, huh? ๐
banks are credit institutions which means they can create broad money while a non-credit institution or a regular business can issue loans - they must fund it (e.g. raise money, use excess profits) they can't just create those $100, thus expanding the monetary supply