Composition refers to the organization, arrangement, and combination of objects within the borders of a drawing space. For a great drawing, you want to bring the eyes of the viewer toward your center of interest within an aesthetically pleasing composition.
The idea that clockwise motion represents the forward motion of time so powerful that it's hard to look at such a watch or clock without having the slightly unsettling feeling that time is running backwards.
The amount of rotation is called the angle of rotation and is measured in degrees. By convention a rotation counter-clockwise is a positive angle, and clockwise is considered a negative angle. Rays from the point of rotation to any vertex all turn through the same angle as the image is rotated.