Here's why:

* Static Friction: This type of friction acts to prevent an object from moving when a force is applied. Think of a heavy box on the floor. You can push on it with a small force, but it won't move because static friction is equal and opposite to your pushing force.

* Kinetic Friction: This friction acts on an object *while it's moving*. Once you push hard enough to overcome static friction, the box will start to slide, and you'll experience kinetic friction.

Key Points:

* Static friction is a "holding force" that keeps things stationary.

* The force of static friction can vary up to a maximum value (depending on the surfaces and the normal force pressing them together).

* Once the applied force exceeds the maximum static friction, the object will start to move.

Let me know if you'd like more detail on friction!