Traditionally, in horology, the term clock was used for a striking clock, while a clock that did not strike the hours audibly was called a timepiece. This distinction is no longer made. Watches and other timepieces that can be carried on one's person are usually not referred to as clocks. Spring-driven clocks appeared during the 15th century.
Clocks have different ways of displaying the time. Analog clocks indicate time with a traditional clock face, with moving hands.