A customer identification program is like a secret handshake that banks and other financial companies use to make sure they know who their customers are. Just like you might have a secret password or a special handshake with your best friend, banks have their own special ways of figuring out who their customers are so they can be safe and secure when using their services.
When you want to open a bank account, the bank needs to know who you are. They will ask you to show them some identification, like your birth certificate or driver's license. This is part of the customer identification program. Once they know who you are, they will keep track of your account and make sure nobody can pretend to be you.
If you try to do something unusual with your account, like withdrawing a large amount of money or sending money to a strange place, the bank might want to verify your identity again. This is all to make sure that nobody else is using your account or pretending to be you.
In short, a customer identification program is like a secret code that banks use to protect you and make sure that they know who you are.