A Power Amplifier is an electronic device that increases the power of a signal, making it stronger for transmission or driving speakers. It takes a weak input signal and boosts it to a level suitable for driving loads, such as speakers in audio systems or antennas in communication devices. These amplifiers are commonly used in various applications, including audio equipment, broadcasting, and telecommunications. They are essential for ensuring that signals can travel long distances or produce sufficient sound levels in public address systems, enhancing overall performance and clarity.