Look at the tiles as if you are looking in a mirror.

Imagine yourself inside a cube with 6 faces: up, down, left, right, front, and back

Imagine a line from your head to your feet connecting the top face and the bottom face.  The Y-Axis is Yellow

Imagine a line running through your shoulders connecting the left and right face.  Thats the X-axis.  It’s blue.

Imagine a line running from in front of your heart to behind your back.  It’s the Z-axis.  It’s red.

A plane can be defined by 2 axes.

3 planes naturally separate the body into halves.

Wall plane: Splits the body into front half and back half.  An arm or prop rotating around the front back axis will be moving in wall plane (green: combines up/down (yellow) and left/right (blue).  Wall plane is one of two vertical planes.

Wheel plane:  Splits the body into left half and right half.  An arm or prop rotating around the left/right axis will be moving in wheel plane (orange: combines up/down axis (yellow) and front/back axis (red).  Wheel plane is one of two vertical planes.

Floor plane:  Splits the body in top half and bottom half.  An arm or prop rotating around the up/down axis will be moving in floor plane (purple: combines front/back axis (red) and left/right axis (blue).  Floor plane is the only horizontal plane (sometimes called ceiling plane or horizontal plane).