+An **order parameter** is a macroscopic measure that quantifies the degree of order within a physical system. Its value changes dramatically across a [Phase Transition](/wiki/phase_transition), distinguishing between different states of matter. It often becomes non-zero in an ordered phase, reflecting a form of [Symmetry Breaking](/wiki/symmetry_breaking).
+## See also
+- [Critical Phenomena](/wiki/critical_phenomena)
+- [Statistical Mechanics](/wiki/statistical_mechanics)
+- [Critical Point](/wiki/critical_point)