Radar works by emitting radio waves, which travel through the air, reflect off objects, and return to the radar antenna. The radar system then analyzes the time it took for the signals to return and the strength of the reflected waves to determine the distance, direction, and speed of the object. This data is then used to create a radar image or plot that provides the operator with detailed information about their surroundings. Radar is crucial in environments where visibility is limited, ensuring safe navigation for vessels and aircraft.