The phenomenon you are referring to is called the Pauli Exclusion Principle, not Pauli blocking.
The Pauli Exclusion Principle is a fundamental principle in quantum mechanics, named after the physicist Wolfgang Pauli. It states that no two identical fermions (particles with half-integer spin, such as electrons, protons, and neutrons) can occupy the same quantum state simultaneously.
In other words, if two fermions are in the same system, they cannot have the same set of quantum numbers. This principle is a consequence of the antisymmetry of the wave function for identical particles. It ensures that fermions have distinct energy levels, leading to the structure of electron shells in atoms, the stability of matter, and many other important properties.
The Pauli Exclusion Principle plays a crucial role in determining the behavior of electrons in atoms, the formation of chemical bonds, and the properties of matter. Without this principle, electrons would all occupy the lowest energy states in an atom, and the structure and diversity of matter as we know it would not exist.