Chime is an online bank account but not like a traditional bank or checking account where you get checks to write out.
With a chime bank account you can have your money direct deposited to the chime account free of charge and with the chime card you can withdraw money from any ATM or even bank for a fee.
Or you can use your chime bank account card to pay bills with or buy things online or in the store just like you would with a regular bank checking account debit card.
So yes in a way chime is a checking account but without the checks which makes it a better and cheaper alternative to traditional bank accounts.
There's no physical location you can go to for a bank with the chime bank account because it's all done online even though they do have an office but it's not a traditional checking account.