Simple explanation of a digital camera.
As you probably know, the world is going digital (computers, TVs, phones, radios etc).
Digital is the format used to store information by computers.
Old cameras that used film had paper in the back that reacted to light, the more light the more reaction. The paper became a negative that was then printed to become a photo.
With a digital camera it has a very small computer in the back that reacts to light instead of film.
Once it has "composed" the picture it saves it as a digital image, and it saves it on a memory card.
Once you have taken say 20 pictures they are all stored on the memory card.
You can then copy the pictures from the memory card to your computer.
Once on the computer you can look at them, print them, manipulate the pictures in various ways and so on.
Once they are on the computer you can delete them from the camera's memory card and start filling it up again.
Generally digital camera are easy to use.
If you buy your grandson one for Xmas ask him to show you how it works and how you get images from the camera to the computer.