the.com/interaction
Two things touch, and neither leaves quite the same.
means A reciprocal exchange where two or more things act on each other and respond.
from Latin inter (between) plus actio (a doing) — literally a doing-between, formalized in English science around the 1800s.
Physics coreAll four forces of nature are just interactions.
Statistics twistWhen two variables combine to surprise you.
Not actionRequires a response, not just a push.