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 linear amplifiers ideal for applications where signal integrity is crucial, such as in audio and radio frequency systems. These amplifiers operate in a linear region of their transfer function, ensuring minimal distortion. Common types of linear amplifiers include Class A, Class B, and Class AB amplifiers, each with different efficiency and performance characteristics. They are widely used in various fields, including telecommunications and broadcasting.