Clockwork in the context of Solar dial

A mainspring is a spiral torsion spring of metal ribbon—commonly spring steel—used as a power source in mechanical watches, some clocks, and other clockwork mechanisms. Winding the timepiece, by turning a knob or key, stores energy in the mainspring by twisting the spiral tighter. The force of the mainspring then turns the clock's wheels as it unwinds, until the next winding is needed. The adjectives wind-up and spring-powered refer to mechanisms powered by mainsprings, which also include kitchen timers, metronomes, music boxes, wind-up toys and clockwork radios.

Mainsprings appeared in the first spring-powered clocks, in 15th-century Europe. The mainspring replaced the weight hanging from a cord wrapped around a pulley, which was the power source used in all previous mechanical clocks.

Chronometry or horology (lit. 'the study of time') is the science studying the measurement of time and timekeeping. Chronometry enables the establishment of standard measurements of time, which have applications in a broad range of social and scientific areas. Horology usually refers specifically to the study of mechanical timekeeping devices, while chronometry is broader in scope, also including biological behaviours with respect to time (biochronometry), as well as the dating of geological material (geochronometry).

Horology is commonly used specifically with reference to the mechanical instruments created to keep time: clocks, watches, clockwork, sundials, hourglasses, clepsydras, timers, time recorders, marine chronometers, and atomic clocks are all examples of instruments used to measure time. People interested in horology are called horologists. That term is used both by people who deal professionally with timekeeping apparatuses, as well as enthusiasts and scholars of horology. Horology and horologists have numerous organizations, both professional associations and more scholarly societies. The largest horological membership organisation globally is the NAWCC, the National Association of Watch and Clock Collectors, which is US based, but also has local chapters elsewhere.

An orrery (/ˈɒr.ə.ri/ ) is a mechanical model of the Solar System that illustrates or predicts the relative positions and motions of the planets and moons, usually according to the heliocentric model. It may also represent the relative sizes of these bodies; however, since accurate scaling is often not practical due to the actual large ratio differences, it may use a scaled-down approximation. The Greeks had working planetaria, but the first modern example was produced c. 1712 by John Rowley. He named it "orrery" for his patron Charles Boyle, 4th Earl of Orrery (in County Cork, Ireland). The plaque on it reads "Orrery invented by Graham 1700. Improved by Rowley and presented by him to John [sic] Earl of Orrery, after whom it was named at the suggestion of Richard Steele."

Orreries are typically driven by a clockwork mechanism with a globe representing the Sun at the centre, and with a planet at the end of each of a series of arms.

A lighthouse keeper or lightkeeper is a person responsible for tending to and caring for a lighthouse, particularly the light and lens in the days when oil lamps and clockwork mechanisms were used. Lighthouse keepers were sometimes referred to as "wickies" because of their job trimming the wicks.

An animatronic is a puppet controlled electronically to move in a fluent way. Animatronics are the modern adaptation of the automaton and are often used for the portrayal of characters in films, video games, and theme park attractions.

Animatronics are a multidisciplinary field integrating puppetry, anatomy and mechatronics. Animatronic figures can be implemented with both computer and human control, including teleoperation. Motion actuators are often used to imitate muscle movements and create realistic motions. Figures are usually encased in body shells and flexible skins made of hard or soft plastic materials and finished with colors, hair, feathers and other components to make them more lifelike. Animatronics stem from a long tradition of mechanical automata powered by hydraulics, pneumatics and clockwork.

A watch is a timepiece carried or worn by a person. It is designed to maintain a consistent movement despite the motions caused by the person's activities. A wristwatch is worn around the wrist, attached by a watch strap or another type of bracelet, including metal bands or leather straps. A pocket watch is carried in a pocket, often attached to a chain. A stopwatch is a type of watch that measures intervals of time.

During most of their history, beginning in the 16th century, watches were mechanical devices, driven by clockwork, powered by winding a mainspring, and keeping time with an oscillating balance wheel. These are known as mechanical watches. In the 1960s the electronic quartz watch was invented, powered by a battery and keeping time with a vibrating quartz crystal. By the 1980s it had taken over most of the watch market, in what became known as the quartz revolution (or the quartz crisis in Switzerland, whose renowned watch industry it decimated). In the 2010s, smartwatches emerged, small wrist-worn computers with touchscreens and with functions that go far beyond timekeeping.

The clockwork universe is a concept which compares the universe to a mechanical clock. It continues ticking along, as a perfect machine, with its gears governed by the laws of physics, making every aspect of the machine predictable. It evolved during the Enlightenment in parallel with the emergence of Newton's laws governing motion and gravity.

In horology, a movement, also known as a caliber or calibre (British English), is the mechanism of a watch or timepiece, as opposed to the case, which encloses and protects the movement, and the face, which displays the time. The term originated with mechanical timepieces, whose clockwork movements are made of many moving parts. The movement of a digital watch is more commonly known as a module.

In modern mass-produced clocks and watches, the same movement is often inserted into many different styles of case. When buying a quality pocketwatch from the mid-19th to the mid-20th century, for example, the customer would select a movement and case individually. Mechanical movements get dirty and the lubricants dry up, so they must periodically be disassembled, cleaned, and lubricated. One source recommends servicing intervals of: 3–5 years for watches, 15–20 years for grandfather clocks, 10–15 years for wall or mantel clocks, 15–20 years for anniversary clocks, and 7 years for cuckoo clocks, with the longer intervals applying to antique timepieces.