Control banding is when grown-ups use their smartness and experience to figure out how to keep you safe when you play with toys that could hurt you.
They imagine all the different toys you might play with and the danger they could have, and then they make 'bands' or rules to keep you safe. For example, they might say that you can only play with sharp toys if you wear gloves or that you can only play with chemical toys if you wear a mask.
This way, you don't have to worry about getting hurt or sick, and you can have fun playing with toys without worrying.