When two forces acting on an object are equal and opposite, it's called equilibrium.

Here's why:

* Equal forces: The forces have the same magnitude (strength).

* Opposite direction: The forces act in directly opposite directions.

This results in a net force of zero, meaning the object will either:

* Remain at rest: If it was stationary to begin with.

* Continue moving at a constant velocity: If it was already in motion.