A superfluid is a phase of matter that exhibits unique properties, such as the ability to flow without viscosity. This means it can move through tiny openings and around obstacles without losing energy, unlike ordinary fluids. Superfluidity occurs at extremely low temperatures, close to absolute zero, where quantum effects become significant. One of the most well-known examples of a superfluid is helium-4, which becomes superfluid below 2.17 Kelvin. In this state, it can climb the walls of its container and form a thin film, defying gravity. Superfluidity is a fascinating phenomenon that helps scientists understand quantum mechanics and the behavior of matter at low temperatures.