A quartz clock is a timekeeping device that uses a small piece of quartz crystal to keep accurate time. When electricity passes through the crystal, it vibrates at a precise frequency, which helps regulate the clock's movement. This technology allows quartz clocks to maintain accuracy within a few seconds per month. Quartz clocks are popular due to their reliability and low cost. They are commonly found in various devices, including wall clocks, wristwatches, and digital timers. The invention of the quartz clock in the 1920s revolutionized timekeeping, making it more precise than traditional mechanical clocks.