The Degrees of Freedom (DOF) of a mechanical system is the minimum number of independent parameters (or coordinates) needed to completely define its position and orientation in space.

Think of it as the number of independent ways a system can move.

2D plane (Planar):

A free-floating object has 3 DOF:

1. Translation along the X-axis

2. Translation along the Y-axis

3. Rotation about the Z-axis (perpendicular to the plane)

Click here to experiment with DOF simulator in 2D plane

In 3D space (Spatial):

A free-floating object has 6 DOF:

1. Translation along the X-axis

2. Translation along the Y-axis

3. Translation along the Z-axis

4. Rotation about the X-axis

5. Rotation about the Y-axis

6. Rotation about the Z-axis

Click here to experiment with DOF simulator in 3D space