Okay kiddo, do you know what 3D means? It means having three dimensions, like length, width, and height. Digital 3D is like that too, but it's on a computer.
So, let's say you want to make a picture of a ball in real life. You could use a regular camera to take a picture of the ball, and it would look flat because the camera only sees in two dimensions. But with digital 3D, you can create a ball on the computer that looks like it's 3D because you can move it around and see all sides of it.
When you make something in digital 3D, you use special software that lets you design it in three dimensions on your computer screen. You can make it look like it has different shapes and sizes, and even change the colors and textures.
People use digital 3D for a lot of things, like making movies, video games, and even designing things like buildings and cars. It's really cool because it lets you create and manipulate things that you wouldn't be able to see otherwise.
So that's digital 3D, pretty neat, huh?