Z-axis

Z-axisWhen referring to a three-dimensional plane, a z-axis refers to the depth of a three-dimensional object. In the illustration the z-axis plane goes front to back and intersects with the y-axis and x-axis. A good example of where the z-axis is used on a computer is in computer games or other 3-D environments, where you have a game character or other object moving in a 3-D world.

Also see: 3-D, Axis, X-axis, Y-axis