A response is when someone is talking and you or the other person talk back and respond to what the other person had said.
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A response is an animal's...
It's just a way of saying that a neuron (or sensory cell) can either (only) respond or not respond (depending on the strength of the stimuli). Which is why your nervous system is said to be pulse...
A conscious response is something you choose to do (e.g. waving to a friend) whereas a reflex response is something your body does automatically (e.g. move your hand away when you touch a hot plate)