Final answer:
John was charged a fee for using an Interac ATM because it is outside of his bank's network, which typically incurs additional charges.
Step-by-step explanation:
John has two ATM transactions but only one of them has a fee because Interac is an out-of-network ATM and First Bank charges customers if they use out-of-network ATMs. Banks serve as financial intermediaries by facilitating transactions and offering different accounts for various needs, such as checking accounts for easy access to funds with a debit card and savings accounts that accrue interest. Fees, like the one John encountered, are charged by banks as part of the process of providing these convenient services and ensuring the security of financial transactions.