Disc number refers to the number assigned to a specific disc in a set of discs like CDs or DVDs. Think of it like the number on your favorite toy block or puzzle piece. When you have a big set of toys, it can be difficult to keep track of which one is which, so we give each one a special number.
Just like how we number our toy blocks, we number each disc so we can keep track of them. For example, if you have ten CDs in a set, each one might have a number from 1 to 10 on it. This helps you know which disc to use if you want to listen to a specific song or watch a specific movie.
So, next time you see a disc number on a CD or DVD, just remember that it's like a special toy block number helping you keep track of all your fun toys!