DiagramA user interface term for a representation of some group of information that at least partially makes use of structural or symbolic representation. The study of diagrams has become particularly interesting in recent years, and programmatic generation of them is in TUNES' interface generation's interest.
In category theory a diagram is a graph where edges are labelled with morphisms and vertices are labelled with objects, in a way that typing of morphisms is respected. Formally, a diagram in a category C is a functor from the free category generated by the graph to C. A commutative diagram is a diagram where some equation holds. The formal definition is the same, where the free category is suitably quotiented by the congruence induced by the equations.