An amplifier circuit is an electronic circuit that increases the amplitude of a signal. Synonyms for amplifier circuit can include signal amplification circuit, signal boost circuit, or signal enhancement circuit. Other words to describe an amplifier circuit might include a power amplifier circuit or an audio amplifier circuit. Amplifier circuits are essential components in many electronic devices such as radios, televisions, and speakers. Additionally, amplifier circuits can be found in a wide range of applications ranging from medical equipment to automotive systems. Regardless of the synonym used to describe an amplifier circuit, they all serve the same fundamental purpose, which is to increase the amplitude of a signal.