Clockwise and Counterclockwise
Clockwise means moving in the direction of the hands on a clock.
Try it yourself:
Faucets (taps) get closed, and most screws and bolts get tightened by turning clockwise.
Counterclockwise / Anticlockwise
The opposite direction is called counterclockwise in the US (or anticlockwise in the UK).
Angles from a line are measured counterclockwise (and a negative angle goes clockwise):
Such long words deserve to be shortened.
So clockwise can be shortened to CW.
And counterclockwise to CCW (or maybe ACW for anticlockwise).