I've run across op-amps and have seen some of the circuits where op-amps are used to amplify or invert a signal. But what is the point of a voltage follower? That doesn't make much sense. One voltage in, same voltage out. What am I missing here?
A voltage follower is used when a high impedance source needs to drive a low impedance load.
For example, let's say we have the output of a 1M ohm oscillscope probe and we want to drive this signal into a 50 ohm oscillosope input. An Op Amp voltage follower can be placed at the output of the probe.
if i am correct, its also called a Buffer Amplifier, or a voltage buffer, so that the input and output are the same voltage regardless of impedance. Without this, you would have a mismatch, and that would be bad for your circuit.