Radar uses radio waves to detect objects by determining their range, altitude, direction, or speed. It transmits pulses of radio waves that bounce off objects and return to the radar dish, allowing it to identify features about the detected object. Radar was developed secretly before WWII and has since become a highly diverse technology with applications in fields like air traffic control, astronomy, defense systems, and more. It provides crucial positioning information to various industries by identifying an object's bearing and range from the radar scanner.