A parking orbit is a relatively stable orbit around a celestial body that is used as a temporary resting place for a spacecraft or satellite before it moves on to its intended destination. There are several synonyms for the term, including holding orbit, waiting orbit, standby orbit, and rest orbit. These terms describe the same concept of a low-energy orbit that allows a spacecraft to maintain a certain distance from a planet or moon without requiring constant rocket thrust. While the term parking orbit is the most commonly used in space missions, it is always good to know these synonyms to better understand space exploration terminology.