Money exchanger or exchanger's ?

English as a Second Language English for Beginners
1

Hi.

What is the difference between
Exchanger and exchanger’s ?
Is the final s for possessive?

What do you call the machine that we can
Withdraw money from?

2

There is no other reason for using an apostrophe + s with that word.

Cashpoint / ATM / Cash Machine / Cash Withdrawal Machine / Hole In The Wall (colloquial term)