We first deal with rotations which are characterized by the fact that the axis of rotation is firmly anchored in space and perpendicular to the plane of motion. The quantities to be investigated, such as angular velocity, torque or angular momentum, take on a particularly simple form under these conditions, which show many analogies to linear motions („translations”) in one dimension. In the second part, the requirement of a fixed spatial axis is dropped, and the statements and laws are extended to the general case.