Degenerate matter is a state of ultra-dense matter whose pressure support is provided by quantum mechanical effects, specifically electron or neutron degeneracy pressure, rather than by thermal gas pressure. This resistance to gravitational collapse arises because the Pauli Exclusion Principle dictates that no two particles can occupy the same quantum state. When gravity attempts to compress the matter beyond the point where thermal energy can counteract the force, the particles are forced into higher, unoccupied energy states, creating an outward quantum pressure that resists further compression. This state of matter is observed in the astrophysical remnants of stars that have exhausted their nuclear fuel and are undergoing gravitational contraction.