What's Jog-Wheel? What's Shuttle-Wheel?
In the above, the circle with a dent is the jog wheel. You can stick a finger on it and turn the wheel.
The outer ring is the shuttle wheel.
What is jog wheel?
Jog wheel is a wheel used in video editing. It lets you forward/backward movie frames, by the speed you turn wheel. When you stop moving the wheel, the movie is paused.
You can watch video sections in slow motion at whatever speed you want, forward or backward. The frames flow with the speed you rotate the wheel.
What is shuttle ring?
Shuttle ring lets you change the direction of play in high speeds to positions you want. The more twisted the wheel is clockwise, the faster is your fast forward. If you twist it anti-clockwise, you control speeds in backward direction.
When your hand leaves the knob, it springs back to the original neutral position.
Jog/Shuttle wheel was popular with the VHS days. They usually are on the remote of expensive VHS players. Professional movie editing hardware always have it, still.
Griffin PowerMate Multi-Media Control Knob
This function as a jog wheel, or volume control. It can be also pressed as a button, default to mute.