A computer module is like a lego block that goes into a toy car. It helps the car move and do things like turn on its lights or beep its horn. Similarly, a computer module is a small piece of a computer that helps it do things like run programs, store information, or connect to Wi-Fi.
Think of a computer like a big puzzle with lots of different pieces that all work together. The computer module is one of those pieces. Sometimes a computer might need a new module, just like a toy car might need a new lego block. When that happens, you can take out the old module and put in a new one. It's kind of like changing a battery in a toy, but instead of a battery, it's a piece of the computer.
Computer modules come in many different shapes and sizes, depending on what they do. Some are small, like a pen cap or a piece of gum. Others are bigger, like a deck of cards or a block of cheese. No matter what size they are, they all help the computer work better so you can play games, do homework, or watch videos on it.