What are degrees of freedom?

Degrees of freedom are the number of ways something can move or change.

Imagine you're playing with a toy car on the floor. If it's just sitting there, it has 2 degrees of freedom, it can move left and right, or forward and backward. But if the toy car is on a track that only goes straight, then it only has 1 degree of freedom, it can only go forward and backward.

Now think about a robot arm. If it’s just a single arm that can bend at the elbow, it has 1 degree of freedom, it can move up and down. But if it has two joints, like an elbow and a wrist, then it has 2 degrees of freedom, it can move in two different ways.

Each time something gets more flexible or more parts, it usually gets more degrees of freedom, just like how you have more choices when you have more toys to play with.