A linear amplifier is an electronic device that increases the power of a signal while maintaining its original waveform. This means that the output signal is a faithful reproduction of the input signal, making it ideal for applications where signal integrity is crucial, such as in audio and radio frequency systems. Linear amplifiers are commonly used in broadcasting, telecommunications, and audio equipment. These amplifiers operate in a linear region of their output characteristics, ensuring minimal distortion. They are typically more complex and less efficient than other types of amplifiers, like class D amplifiers, but are preferred when high fidelity is required.