Two-dimensional rotation can occur in two possible directions or senses of rotation. Clockwise motion (abbreviated CW) proceeds in the same direction as a clock's hands relative to the observer: from the top to the right, then down and then to the left, and back up to the top. The opposite sense of rotation or revolution is (in Commonwealth English) anticlockwise (ACW) or (in North American English) counterclockwise (CCW). Three-dimensional rotation can have similarly defined senses when considering the corresponding angular velocity vector.

Before clocks were commonplace, the terms "sunwise" and the Scottish Gaelic-derived "deasil" (the latter ultimately from an Indo-European root for "right", shared with the Latin dexter) were used to describe clockwise motion, while "widdershins" (from Middle Low German weddersinnes, lit. "against direction") was used for counterclockwise motion.

The terms clockwise and counterclockwise can only be applied to a rotational motion once a side of the rotational plane is specified, from which the rotation is observed. For example, the daily rotation of the Earth is clockwise when viewed from above the South Pole, and counterclockwise when viewed from above the North Pole (considering "above a point" to be defined as "farther away from the center of earth and on the same ray").

Clocks traditionally follow this sense of rotation because of the clock's predecessor: the sundial. Clocks with hands were first built in the Northern Hemisphere (see Clock), and they were made to work like horizontal sundials. In order for such a sundial to work north of the equator during spring and summer, and north of the Tropic of Cancer the whole year, the noon-mark of the dial must be placed northward of the pole casting the shadow. Then, when the Sun moves in the sky (from east to south to west), the shadow, which is cast on the sundial in the opposite direction, moves with the same sense of rotation (from west to north to east). This is why hours must be drawn in horizontal sundials in that manner, and why modern clocks have their numbers set in the same way, and their hands moving accordingly. For a vertical sundial (such as those placed on the walls of buildings, the dial being below the post), the movement of the sun is from right to top to left, and, accordingly, the shadow moves from left to down to right, i.e., counterclockwise. This effect is caused by the plane of the dial having been rotated through the plane of the motion of the sun and thus the shadow is observed from the other side of the dial's plane and is observed as moving in the opposite direction. Some clocks were constructed to mimic this. The best-known surviving example is the Münster astronomical clock, whose hands move counterclockwise.

Occasionally, clocks whose hands revolve counterclockwise are sold as a novelty. One historic Jewish clock was built that way in the Jewish Town Hall in Prague in the 18th century, using right-to-left reading in the Hebrew language. In 2014 under Bolivian president Evo Morales, the clock outside the Legislative Assembly in Plaza Murillo, La Paz, was shifted to counterclockwise motion to promote indigenous values.

Typical nuts, screws, bolts, bottle caps, and jar lids are tightened (moved away from the observer) clockwise and loosened (moved towards the observer) counterclockwise in accordance with the right-hand rule.

To apply the right-hand rule, place one's loosely clenched right hand above the object with the thumb pointing in the direction one wants the screw, nut, bolt, or cap ultimately to move, and the curl of the fingers, from the palm to the tips, will indicate in which way one needs to turn the screw, nut, bolt or cap to achieve the desired result. Almost all threaded objects obey this rule except for a few left-handed exceptions described below.

The reason for the clockwise standard for most screws and bolts is that supination of the arm, which is used by a right-handed person to tighten a screw clockwise, is generally stronger than pronation used to loosen.