Okay kiddo, imagine you are playing at the park with your friends and someone starts breaking the rules. The park ranger comes over and asks you if you saw who did it. You want to help, but you also don't want to get in trouble or say something that might not be true, right?
Well, in a similar way, police officers have a rule called the Garrity Warning. It's like a promise or agreement they make with themselves to protect their own rights when they are being investigated for something they did while on the job.
When a police officer is being questioned about something they did, the Garrity Warning means that they have to answer truthfully, but the things they say can't be used against them in a criminal court case. This is because police officers have a special job where they need to use their power to help protect people and keep them safe.
So, just like you might want to help the park ranger, but also don't want to get yourself or your friends in trouble, police officers need to have this Garrity Warning to help them do their jobs in the right way and keep everyone safe.