Operational Amplifier : Amplification :: Comparator : ?

An op‑amp is mainly used to amplify a small voltage into a larger one, so its key function is amplification. A comparator, on the other hand, takes two input voltages and decides which is higher, then drives its output high or low accordingly. Thus the counterpart to amplification in this analogy is comparison, producing a binary decision rather than a scaled voltage. For example, if a comparator receives +2 V on its non‑inverting input and +1 V on its inverting input, its output will go high, indicating that the first input is larger.