My background is software, and my knowledge of electronics is pretty limited. I'm trying to understand the purpose of a unity gain amplifier.
As I understand it, the purpose is to match output and input impedance. If a device providing input voltage/current to the op-amp has high output impedance, then it must draw more power from its source for any given output than a device with lower output impedance, is that right?
If so, I don't see the problem with feeding its output voltage/current into a device with low input impedance. Wouldn't the input device just take what it needs and be happy?
Would someone mind showing me what I'm missing? Why is the op-amp needed?