An amplifier is an electronic device that boosts the voltage, current, or power of a signal. Commonly used in wireless communications, broadcasting, and audio systems, amplifiers play a key role in strengthening weak signals. They are generally classified into weak-signal amplifiers and power amplifiers.Different types of amplifiers, such as power, transistor, operational, fully differential, video, and microwave amplifiers, serve various purposes. Most often, they are used in audio and video applications to amplify signals to a usable level.