Clocks have been used for centuries around the world, as a way to keep time and measure the movement of the seasons. The clock (Pendeluhr) is one of the oldest human inventions, although the original devices used for time keeping would have looked very different to the ones of today. During the last 100 years, we have seen the development of a number of variations on the classic clock design, through the advent of highly advanced mechanics and digital technology. Clocks are used all around the world today, in businesses, homes, and in public spaces. Clocks can be classified according to the type of display they use and the method of time keeping that they utilise. Some variations on the classic clock design include analog clocks, digital clocks, water clocks, auditory clocks, musical clocks, alarm clocks, atomic clocks, binary clocks, oil lamp clocks, radio clocks, pendulums, quantum clocks, and hourglass clocks among others.

The original clocks were based on the sundial, a mechanism for measuring the time of day through the shadow of the sun. Sundials and local variations were used throughout the world in ancient times, with well constructed versions able to measure time with a reasonable degree of accuracy. Water clocks were another old mechanism that was used for telling time, with some examples known to have been used in Babylon, Egypt, Indian and China. However, it was not until much later in human history in the 13th century that the earliest version of the modern mechanical clock came into existence. The word clock comes from the Latin word clocca, which translates to the English work ‘Bell’. Clocks were developed in the 13th century, with their designs refined over the next few hundred years.

Today in the 21st century, there are a number of variations to the classic mechanical clock form. Perhaps the most obvious evolution of the mechanical clock is the digital clock, which came into fruition in the 1960s. Digital clocks are commonly used as household clock, as well as in personal watches and time keeping devices. However, perhaps the biggest revolution with digital clocks is in terms of their integration with other electronic devices, with items like the alarm clock and the inclusion of clocks on computers, televisions, and other devices. The classic clock design continues to evolve and change in modern times, with digital technology used in the majority of new clock products.