Linked from
The 30 pages that link to Commutator, each with the reason it gives.
Lie algebraRelated: Matrix commutators are the standard source of Lie brackets.
Lie bracketRelated: The operator commutator is the standard model of a Lie bracket.
Solvable groupBroader topic: Commutators generate each step of the derived series.
Pascual JordanRelated: Commutators express the algebraic relations at the heart of matrix mechanics.
Rubik's CubeRelated: Commutators can reposition a few pieces while largely preserving others.
Ehrenfest theoremRelated: Commutators encode the dynamical terms in the general theorem.
Golden–Thompson inequalityRelated: When this vanishes, the inequality becomes equality.