Buffer amplifier
In electronics, a buffer amplifier is a unity gain amplifier that copies a signal from one circuit to another while transforming its electrical impedance to provide a more ideal source (with a lower output impedance for a voltage buffer or a higher output impedance for a current buffer). This "buffers" the signal source in the first circuit against being affected by currents from the electrical load of the second circuit and may simply be called a buffer or follower when context is clear.