Stable state, also known as STASIS, is a term used to describe a situation in which a system or process remains unchanged over a period of time. STASIS is often used to refer to a state of equilibrium, where the forces acting on the system are balanced and the system is not changing. Stable state can also refer to a situation in which a system is not changing, but is still in flux, such as when a system is undergoing slow changes over time.