Copy-on-write

Copy-on-write is a way to save time and space when you want to make a copy of something. Imagine you have a toy car that you want to copy. Instead of making a whole new car and using up all the materials, you can copy it by using a special magic marker on it. This marker makes an invisible copy. If you want to change the color of the car, you can use the marker to make the copy visible, and then paint it. This is called copy-on-write! It saves time and materials because you only have to copy something when you want to change it. It's like making a copy of a drawing but only using the pencil when you want to make a change.