A cryocooler is a device that is used to cool objects to very low temperatures. There are different types of cryocoolers, such as Gifford-McMahon cryocoolers, pulse-tube cryocoolers, and Stirling cryocoolers. These types of devices are also known as cryogenic coolers, cryo-refrigerators, or cryo-systems. Cryocoolers are commonly used in cryogenic research, medical imaging, and satellite observation equipment. Some other synonyms for cryocoolers include sub-zero coolers, low-temperature coolers, and supercooling devices. Regardless of their name, these coolers play an important role in maintaining very low temperatures for various applications.