轨迹 (guǐ jì) refers to the path or track left by a moving object, such as an orbit or trajectory, and is also used figuratively for the course of events or life. It differs from 轨道 (guǐ dào), which emphasizes a fixed, pre-existing track (like railway rails or a satellite's orbit) rather than the trace left behind. In figurative use, 轨迹 suggests the actual path taken, while 轨道 suggests a prescribed or established course.