The difference between interaction and reaction in design

In a sense, I think interactive design is a combination of multiple reactive elements design.

Firstly, we could interpret reaction as a change or modification of our behavior. It could be physical or psychological. However, after a corresponding behavior came out, actually the whole process of reaction is finished at the same time.
Compared with reaction, interaction seems like a continuously operating feedback loop.
Normal cases like playing in a game, a classic interactive environment, where players could be evaluated and re-evaluated, establish communication, and receive a serial of simulation and information. It is changing, developing and evolving.
When we split out it, we could still find it as a congregation of multiple physical /psychological triggers and receivers, and these two parts are exactly the components in a reaction.