Okay kiddo, have you ever seen your mom or dad go to the store and buy something with their credit card? Well, casinos also use machines that let people pay with their card, but for gambling.
Sometimes, there are bad people who try to steal the information on the card when people use it at the casino. They do this in a sneaky way called skimming.
The bad guy puts a special device on the machine that reads the information on the card when the person slides it in. This way, the bad guy can find out the card number, the expiration date, and the security code on the back.
Then, the bad guy can make a copy of the card and use it to buy things for themselves. The person who has the real card doesn't know this happened until they get their credit card statement and see charges they didn't make.
That's why it's important to be careful and keep an eye on your card whenever you use it at a casino or anywhere else. You can protect yourself by using cash instead of a card, or making sure no one is watching you when you type in your pin number. And always, always check your statements to make sure everything looks ok!