Nodes represent the individual agents and edges define their interconnection.
Individual agents can communicate only along the links specified by the architecture.
An architecture style is a class of architectures characterised by a graph grammar. The rules of the coordinator are statically checked to ensure that they preserve the constraints imposed by the architecture style. Software architecture styles as graph grammars. ACM Press, 1996. Doc 220 Communications of the ACM - Carriero, Gelernter et al.