A cryostat is a device used to maintain very low temperatures for scientific experiments and applications. It typically consists of an insulated chamber that can hold samples, along with a cooling system that uses liquid gases like helium or nitrogen to achieve and sustain these low temperatures. Cryostats are essential in fields such as physics, materials science, and biotechnology. These devices are crucial for studying the properties of materials at low temperatures, which can reveal unique behaviors not observable at higher temperatures. Cryostats are also used in medical applications, such as preserving biological samples, and in superconductivity research, where materials exhibit zero electrical resistance at low temperatures.