Y-axis

When referring to a two and three-dimensional plane, a y-axis or vertical axis refers to the vertical height of a two or three-dimensional object. In the picture to the right, the y-axis plane moves up and down and intersects with the x-axis and z-axis. A good example of where the y-axis is used on a computer is on the mouse. By assigning a value to the y-axis, when the mouse is moved up or down the y-axis value increases and decreases, which allows the computer to know where the mouse cursor is on the screen.

Also see: Axis, X-axis, Z-axis