Alignment is a handful of angles. Here's what each one means.
Camber
How far the wheel tilts in or out when you look at it from the front or back. Negative camber tilts the top of the wheel toward the car.
Toe
Whether the wheels point slightly toward each other or away from each other, like your feet when you stand.
Caster
The forward or backward lean of the steering axis, seen from the side. It affects steering feel and how well the wheel returns to center.
Thrust angle
The direction the rear axle points compared with the centerline of the car. If it's off, the car can "dog track" down the road.
Cheetalign starts with camber and builds toward the full set.