Supercooling refers to the process where a substance is cooled below its freezing point without solidifying, but it is not officially recognized as a distinct state of matter. At extremely low temperatures, such as below 4 Kelvin, matter can enter states like Bose-Einstein condensates or superfluids. Superfluidity is a phenomenon observed in certain liquids at very low temperatures, where they flow without viscosity. The discussion highlights the importance of precise terminology when discussing states of matter and encourages proper communication. Understanding these concepts is essential for grasping advanced physics topics.