Here's why:
* Friction is a force that opposes motion. It arises from the interaction between surfaces in contact.
* It always acts in the opposite direction of the intended motion. If you try to slide a book across a table, friction will act against your push to slow it down.
There are different types of friction, including:
* Static friction: This acts on an object at rest and prevents it from starting to move.
* Kinetic friction: This acts on an object already in motion, slowing it down.
Let me know if you'd like to know more about friction!