Friction and gravity are two important forces that affect the motion of objects. Let's take a closer look at each of them:

Friction: Friction is the force that resists the relative motion between two surfaces that are in contact. It always acts in the opposite direction of the applied force. For example, when you push a book on a table, the frictional force between the book and the table surface opposes the motion, making it harder to slide the book.

Gravity: Gravity is the force of attraction between any two objects with mass. It is responsible for the weight of objects and the motion of celestial bodies. The force of gravity on Earth always acts downwards, pulling objects towards the center of the Earth. A classic example is the force of gravity keeping us firmly grounded on the Earth's surface.

So, friction and gravity are important forces that play a crucial role in our everyday lives and the motion of objects around us.