Buffer Amplifier or simply a buffer is an electronic amplifier that is designed to have an amplifier gain of 1. They are used in impedance matching to maximize energy transfer between circuits or systems. It is also known as voltage follower.
A buffer is a unity gain amplifier packaged in an integrated circuit. Its function is to provide sufficient drive capability to pass signals or data bits along to a succeeding stage.
There are two main kinds of buffer circuits, Voltage buffers and Current buffers. The purposes of each is to isolate the mentioned characteristic to avoid loading the input circuit or source from the output stage.