The equal and opposite forces described by Newton's Third Law are called action-reaction forces.

Here's why:

* Action: One force is the "action" force, which is the initial force applied by one object on another.

* Reaction: The other force is the "reaction" force, which is the equal and opposite force exerted by the second object back on the first.

It's important to remember that these forces always act on different objects. They don't cancel each other out, but they do influence the motion of both objects involved.