A chief compliance officer is someone who makes sure that companies follow all the rules and laws that they are supposed to follow. It's kind of like when your teacher makes sure that everyone in your classroom is following the rules, like sitting quietly and raising their hand to speak.
So, let's say a company makes a lot of money by selling things to people. They have to make sure that they are allowed to sell those things, and that they are telling people the truth about what they are buying. They also have to make sure they are paying their workers fairly and not doing anything that might hurt the environment.
The chief compliance officer's job is to make sure the company is doing everything it's supposed to, and not doing anything it's not supposed to. They check what the company is doing, and if they notice something that isn't right, they tell the people in charge to fix it. That way, the company can keep making money and everyone can be happy that they are doing things the right way.