Dial
A dial is a background used to orient the hands for timekeeping.
Most watches feature a dial, and most dials are decorated with markers, numerals, lettering, and so on. Many dials are decorated using guillochage in patterns and textures. Some watches have additional smaller dials for small seconds or complications known as subdials. A few special watches, such as the Jaeger-LeCoultre Reverso Duoface have multiple main dials and subdials.
Watches with a hole in the dial through which the movement (especially the escapement) can be viewed are called open heart, while watches with broader open surfaces are called skeleton.