They affect the acceleration of bodies.
Gravity and friction there are others also like magnetism for example..
Normal, Friction, Tension, and Elastic Forces.
Contact forces must be touching whatever they are acting on the others have a field of influence around them; ie they don't have to touch to act on something
Air resistance and friction are similar in that they both act to oppose motion. Air resistance occurs when an object travels through the air, while friction occurs when two surfaces come into contact. Both forces dissipate energy and slow down the movement of objects.
They are forces of nature..
friction forces
Sliding Friction
Friction produces heat. The other forces produce motion or stress.
They are forces of nature.
Mainly friction.
Friction
Four forces in static friction are:- 1. Weight 2. Tension 3. Normal Force 4. Static Friction