Okay kiddo, imagine you have a secret treasure box that you don't want anyone to see, except mommy and daddy. This secret box has a secret code that only you and mommy and daddy know. You also make sure that the box is always in a safe place where no one can just take it without your permission.
The same thing happens for some important information in the government. There are things that the government doesn't want people to know, like how to make bombs or to protect important people. The government has also a secret code and safe place to keep these secret things so that nobody gets them, and only the people who need to know can access them.
The Classified Information Procedures Act is like some very strict rules that the government has to follow when handling these secret things. This law makes sure that everything is kept safe and that only people who really need to know get access to these secrets. Plus, if someone breaks these rules or tells the secrets to someone who isn't supposed to know, they can get in big trouble with the law.
Just like your treasure box, some secrets need to be kept safe, and the government takes it very seriously to keep them safe!