A sundial shows the time by displaying the position of a shadow on a (usually) flat surface, which has markings that correspond to the hours.
Sundials can be horizontal, vertical, or in other orientations.
Watches and Timepieces
Timepieces that can be worn or carried on one’s person are often distinguished from clocks by calling them watches. This includes wrist watches, watch necklaces, pocket watches, and ring and brooch watches.