What is a Voltage Follower?
A voltage follower (also known as a buffer amplifier, unity-gain amplifier, or isolation amplifier) is an op-amp circuit whose output voltage is equal to the input voltage (it “follows” the input voltage). Hence a voltage follower op-amp does not amplify the input signal and has a voltage gain of 1.
The voltage follower provides no attenuation or amplification—only buffering.
A voltage follower circuit has a very high input impedance. This characteristic makes it a popular choice in many different types of circuits that require isolation between the input and output signal.
Below figures shows implementation of Voltage follower in Proteus design suite. You can see how the output voltage is approximately equal to the given input voltages.