Final answer:
Real forces have a physical origin and result in accelerations in accordance with Newton's laws, while fictitious forces arise in accelerating frames of reference and lack a physical reaction force.
Step-by-step explanation:
To discriminate real forces from fictitious forces, we need to consider their origins and the effects they produce. Real forces, such as gravitational pull, lift, and thrust, have a physical origin and are present regardless of the observer's frame of reference. They follow Newton's laws of motion and result in accelerations that reflect the interaction between two objects. On the other hand, fictitious forces are experienced due to an observer being in a noninertial frame of reference, such as experiencing the sensation of being pushed outwards while on a merry-go-round or feeling pushed backward when a car accelerates.
Fictitious forces are caused by acceleration of the reference frame itself, and they do not have a physical reaction force associated with them. For example, the apparent force you feel pushing you to the side when turning a corner in a car is a fictitious force resulting from the car's acceleration and not from a direct physical interaction.