Normal force is an important idea in how things move, especially when we talk about the different forces on objects.

• The normal force is the push that a surface gives to hold up something that’s resting on it. This force pushes straight up, or "normal," to the surface.

• It helps balance out the force of gravity. For example, when you put a book on a table, gravity pulls the book down. At the same time, the table pushes up with an equal normal force. This balance keeps the book from falling.

• When something is moving, other things can change the normal force, like slopes and friction. On a hill, the normal force gets weaker because only part of gravity pushes straight down against the hill. This change affects how easily things slide down, showing how different forces work together.

• Normal force also affects friction, which is the force that resists sliding. The frictional force can be calculated with this formula: $f_f = \mu N$. Here, $f_f$ means frictional force, $\mu$ is how "sticky" the surfaces are, and $N$ is the normal force.

• Changes in normal force can seriously influence motion. For example, when cars turn, the normal force changes because of curved roads. This helps keep the car stable.

In short, the normal force isn’t just there to hold everything up; it actively controls how things move and how they interact with other forces. Understanding normal force is key to grasping the basics of motion and forces in our world.