Axis

In any field of engineering, constructional, or mathematical sciences, there are three axises: the X-Axis, the Y-Axis, and the Z-Axis. Each one represents a direction in 3-D construction of mathematics. In layman's terms, the X-Axis refers to any horizontal movement (left or right) in the planes. The Y-Axis refers to any vertical movement (up or down) in the planes.

The Z-Axis is different, as it is only involved in 3-D graphing. The Z-Axis refers to any movement through a specified depth. To simplify it further, imagine a perfectly shaped cube (a wooden block, for example), and one of the faces are towards you. The square face has two axises, the X-Axis (horizontal sides) and the Y-Axis (vertical sides). Turning the cube a little, the Z-Axis is revealed as the depth of the cube is shown.
 * The X-Axis determines horizontal movements
 * The Y-Axis determines vertical movements

You use X, Y and Z axis' when resizing, moving and rotating bricks in Roblox Studio.
 * The Z-Axis determines the movement along the depth