The figure below shows the cam nomenclature along with vertical follower.

• Cam profile: Cam profile is outer surface of the disc cam.
• Base circle: Base circle is the smallest circle, drawn tangential to the cam profile.
• Trace point: Trace point is a point on the follower, trace point motion describes the movement of the follower.
• Pitch curve: Pitch curve is the path generated by the trace point as the follower is rotated about a stationery cam.
• Prime circle: Prime circle is the smallest circle that can be drawn so as to be tangential to the pitch curve, with its centre at the cam centre.
• Pressure angle: The pressure angle is the angle between the direction of the follower movement and the normal to the pitch curve.
• Pitch point: Pitch point corresponds to the point of maximum pressure angle.
• Pitch circle: A circle drawn from the cam centre and passes through the pitch point is called Pitch circle.
• Stroke: The greatest distance or angle through which the follower moves or rotates.