Camber is the angle a wheel makes with a vertical axis. Stand 30 feet behind your car and you'll see that the top edges of your rear wheels point towards the center of your car. This is negative camber. Positive is when the top of a wheel points away from the center of the car. Negative camber is good, to a point.

Castor is the angle between the center of rotation of your front wheels when you turn the steering wheel and a vertical axis. The center of rotation is the line connecting the lower ball joint and the center of the upper strut bearing. This axis is always behind(with respect to the front of the car) the vertical axis.