What describes the trajectory of a round during its flight?

The trajectory of a round during its flight is best described as the curved path that the round takes from the moment it leaves the muzzle of the weapon until it impacts the target. This trajectory is influenced by several factors, including the initial velocity of the round, the angle at which it is fired, air resistance, and the effects of gravity.

When discussing trajectory in the context of ballistics, it is important to recognize that the round will not travel in a straight line. Instead, it follows a parabolic path, typically rising initially before descending towards the target. Understanding the trajectory is crucial for accurate aiming and impacts, especially over varying distances.

While details like the maximum speed reached, the total time taken to reach the target, or the angle of launch are important factors in the study of ballistics, they do not directly define the trajectory itself. The essence of trajectory is about the path the round follows, making the option that describes it as a "curved path" the most accurate representation of this concept.