The ATM found in a mall, shop, or casino may be operated by a private company who may have its own charges for the use of the machine. This may be a flat fee per transaction or percentage of the withdrawal amount. Banks often allow free use of their own machines and sometimes have agreements that allow free use of the ATMs of other banks.
When shopping for a bank or checking account, ATM fees are an appropriate feature to review in selecting the kind of account you want. For some the fees can be a significant expense.