In simple terms, joint proprioception means joint position sense. In other words, where is the joint in relation to the body?

Proprioception is really more complex than just one function. Besides joint position, proprioception also helps the joint tell how fast it's moving and in what direction. There's also an ability to sense resistance to the muscles around the joint.

Active motion (you move your arm) and passive motion (someone else moves your arm) are two separate types of joint position sense. Kinesthesia is also a part of proprioception. This is the ability to feel the joint position as you move through space.

Being able to match one arm's movements to the other, called movement replication, is another form of proprioception.