Axis
1. Alternatively referred to as a coordinate axis an axis is an imaginary line that crosses through a point. In a 3-D environment there are three axis's as shown
in the picture to the right. In this picture you can see an X, Y and Z axis, the
X-axis is the horizontal axis, the Y-axis is the vertical axis, and the Z-axis
is the depth axis.
2. An axis or chart axis is the description of values displayed on the side of a chart that describe the values of what is being displayed.
Also see: Absolute coordinates, X-axis, Y-axis, Z-axis