Graphic Design 101 - Chapter 6: Figure/Ground

Every artwork must have two things: Figure and Ground. A figure is an object that the image is focused on, and a ground (also called a background) is the scene surrounding it. There can be more than one figure and ground in an image. There's no limit to how many an image can have. They are the things that allow the image to tell a story and give it meaning. Without them, the image has nothing.

This image is a great example of both figure and ground. In it, the "figure" is the face on the bottom left with an arm, and he's holding an internet browser window showing the sky. The arrows are pointing right at the window. Also, everything is "grounded" nicely.