An atomic clock is a highly precise timekeeping device that uses the vibrations of atoms to measure time. Unlike traditional clocks that rely on mechanical parts or quartz crystals, atomic clocks use the natural frequency of atoms, typically cesium or rubidium, to keep time. This allows them to maintain accuracy to within billionths of a second, making them the most reliable timekeepers available. These clocks are essential for various applications, including global positioning systems (GPS), telecommunications, and scientific research. The accuracy of atomic clocks helps synchronize time across the globe, ensuring that everything from satellite navigation to financial transactions operates smoothly and efficiently.