A clock signal is a timing signal used in digital circuits to synchronize operations. It oscillates between high and low states, creating a regular rhythm that helps coordinate the actions of various components, such as microprocessors and memory. This ensures that data is processed in a precise order and at the right time. In electronic systems, the clock signal is often generated by a crystal oscillator, which provides a stable frequency. The speed of the clock signal, measured in hertz, determines how fast a circuit can operate. A higher frequency allows for quicker processing, making it essential for efficient performance in devices like computers and smartphones.