If you move something, you change its position. If you move your arm, you move it up, down or sideways. Any kind of movement needs a force. Most things don't move, however, and that is because forces mostly balance. Look at this tug of war. If we didn't know that the people were all pulling as hard as they could, we might think they were all doing nothing. We only see movement when one force is bigger than the ones opposing it.

If you sit on a chair, you are putting your weight on the chair. Weight is a force. But the chair is strong, and so the frame is able to push back with a force which exactly matches your weight. But if you were to sit on a chair made of paper you would fall through it because the paper is not strong enough to make a force that can balance your weight.

In a motor car, the force is downwards (the weight) just like you sitting in the chair. But we want to make the car move, so we need to give it a sideways force. But as we do so it is opposed by an equal force called friction. What the engine does is to make a force bigger than friction. Once we get going, the car has to move air out of the way. The air applies a force, too. So the fuel we use up is needed to overcome all of these forces that try to keep things still.

The most important force stopping movement is gravity. This is why, with very little gravity, things just float about in a spaceship. So having balancing forces that stop things moving about until we want them to is, on balance, quite useful.

We can reduce friction. That is, we can make things more slippery. That is what we use oil, soap, grease and other materials for. They are called lubricants.