the.com/response
Proof that something out there registered you exist, for better or worse.
means A reaction, reply, or answer prompted by something said, done, or asked.
from From Latin respondere, to answer or pledge in return — literally a promise made back, as if every reply settles a small debt.
LiturgyCongregations chant fixed responses to the priest.
BiologyOrganisms respond to stimuli; that's basically being alive.
Fight or flightYour fastest response skips conscious thought entirely.