A trajectory is the path that an object follows through space as a function of time, often influenced by forces such as gravity, friction, and propulsion. It is a fundamental concept in physics and engineering, used to predict and analyze the motion of objects ranging from projectiles to spacecraft.
Ballistics is the science that deals with the motion, behavior, and effects of projectiles, often focusing on bullets, missiles, and bombs. It encompasses the study of the dynamics of projectiles in flight, the mechanics of their launch, and the impact they have upon reaching a target.