Bekenstein bound

In physics, the Bekenstein bound (named after Jacob Bekenstein) is an upper limit on the thermodynamic entropyS, or Shannon entropyH, that can be contained within a given finite region of space which has a finite amount of energy—or equivalently, the maximum amount of information that is required to perfectly describe a given physical system down to the quantum level. It implies that the information of a physical system, or the information necessary to perfectly describe that system, must be finite if the region of space and the energy are finite.