Mount the camera on a dolly, Steadicam, or gimbal and move it alongside the subject — a walking person, a moving car — at matching speed. Unlike a pan, where the camera just rotates in place to follow, a tracking shot physically relocates the camera itself.
The result: the subject stays roughly fixed in the frame while the background streams sideways at the speed the camera is covering ground. That streaming background is what sells "we are in motion" — it gives walking, running, and driving scenes their rhythm and sense of accompanying the subject.
It's also called a "dolly shot" from the traditional rail-mounted rig, though these days it's just as often a Steadicam or gimbal operator walking alongside. Uneven ground introduces shake, so stabilization gear is essential to keep the frame smooth.
When to use
Use it for a character walking-and-talking, or a car chase where you want to feel like you're riding along. It costs more in gear and setup than a static shot.