A pedal keyboard is like a special set of buttons that you use with your feet instead of your hands. Just like how you play piano keys with your hands, you can play different notes on a pedal keyboard by pressing down on the pedals with your feet.
Pedal keyboards are often used in churches or big concert halls because they make a really loud sound that can be heard by a lot of people. They can also be used to make different types of sounds, like really deep and low notes, that you can't make with your hands on a regular piano.
Sometimes people use pedal keyboards to play music while they're singing or playing an instrument like a guitar. It can be hard to play both at the same time, but using the pedals with your feet can make it easier.
Overall, a pedal keyboard is just another way to make beautiful music, but it uses your feet instead of your hands to do it.