Joint custody means both of your parents will share taking care of you. This usually happens when your parents are not together anymore and they want to make sure you feel loved and cared for by both of them.
Just like how you have to share toys with your friends, your mom and dad will have to share time with you. You might spend some days with your dad and some days with your mom. This way you get to spend equal time with both parents and don't miss out on their love and attention.
Your parents will make important decisions about your life together, like where you go to school, what doctor to go to, and big decisions about your life. They might not always agree, but they will talk and try to come up with a solution that is best for you.
Even though your parents are not together anymore, they both still love you very much and will continue to take care of you together.