Friction
Mainly friction.
Oppose & Prevent
The two forces that oppose motion are friction and air resistance. Friction is the force that acts opposite to the direction of motion when two surfaces are in contact, while air resistance is the force that opposes an object's motion through the air.
There are many types of forces that oppose motion such as friction, drag and most universal, gravity.
Air resistance and frictional forces typically oppose the motion of a feather. Air resistance pushes against the direction of motion as the feather falls through the air, while frictional forces between the feather and the surface it lands on can also slow down its motion.
Inertia is a property of matter that makes it harder to move, so that is probably what you are thinking of, but technically, forces do not oppose motion. Depending upon the direction in which a force is applied, one force can oppose another force that is acting in an opposite direction, but forces are not opposed to motion as such.
Many other forces can change the shape or motion of an object, while frictional forces primarily oppose motion by creating resistance. Additionally, other forces such as gravitational, electromagnetic, and nuclear forces can act over larger distances compared to the localized effects of friction. Frictional forces also do not have the ability to attract or repel objects like electromagnetic forces do.
This statement is not accurate. In the absence of any external forces, an object in motion will continue to move at a constant velocity due to Newton's First Law of Motion. Opposition to motion arises when there is a force acting on the object that opposes its direction of motion.
Relative motion
Friction.
drag forces, which are forces that oppose the motion of an object through a fluid medium (air or water). These forces are caused by the interaction between the object and the fluid, resulting in a resistance that slows down the object's movement.
Drag and thrust oppose each other in flight. Thrust is the force that propels an aircraft forward, while drag is the force that acts against the motion of the aircraft, slowing it down.