Radar is an abbreviation for "Radio Detection and Ranging", which comes from the original abbreviation of "Radio Aircraft Detection and Ranging". Radar is the term for various detection and tracking methods based on electromagnetic waves in the radio frequency range (radio waves).
A radar is a device which sends out concentrated electromagnetic waves that pick up the echoes reflected from objects and charts these according to different criteria. In this way, a radar can gather information about the objects in the surrounding area. There are various different principles of radar depending on its intended use, such as a weather radar, a harmonic radar and an over-the-horizon radar.