Superfluid helium is a unique state of matter that occurs when helium-4 is cooled to temperatures close to absolute zero, around 2.17 Kelvin. In this state, helium exhibits remarkable properties, such as flowing without viscosity, which means it can move without losing energy. This allows it to climb up the walls of containers and flow through tiny openings. This phenomenon is a result of quantum mechanics, where the atoms in helium behave collectively rather than individually. Superfluid helium is often studied in laboratories and has applications in fields like cryogenics and quantum physics, helping scientists understand fundamental principles of matter.