Here's why:

* Forces are vectors: Forces have both magnitude (how strong they are) and direction.

* Net force is the sum of all forces: To find the net force acting on an object, you add up all the forces acting on it, taking their directions into account.

* Balanced forces cancel out: If the forces are balanced, they have equal magnitudes but opposite directions. This means they add up to zero, resulting in a net force of zero.

Here's an example:

Imagine you push a box with a force of 10 Newtons to the right. Your friend pushes the box from the opposite side with a force of 10 Newtons to the left.

* Force 1: 10 Newtons to the right.

* Force 2: 10 Newtons to the left.

* Net force: 10 Newtons - 10 Newtons = 0 Newtons

Conclusion: The forces are balanced, resulting in a net force of zero. The box will not move.