Architectural patterna Layers GUI windows reports Presentation speech interface (AKA Interface, Ul, view) HTML, XML, XSLT, JSP, Javascript handles presentation layer requests spec workflow session state Application window/page transitions (AKA Workflow, Process consolidation/transformation of disparate Mediation, App Controller) data for presentation handles application layer requests im plementation of domain rules domain services Pos, Inventory Domain(s) services may be used by just one (AKA Business Business Services, Model application, but there is also the possibilit of multi-application servicesArchitectural Pattern: Layers