Concept: The Concept of Application Tiers
"Tiers" can be logical or physical, and are used primarily to categorize deployable parts of the solution (software components), typically based on their underlying technology and where they will be deployed.
Relationships
Related Elements
Main Description

A complete application solution involves software components and other deployable elements in the following "tiers:"

  • Presentation tier
  • Workspace tier
  • Services tier
  • Domain tier

Of the above tiers, each of which is described in more detail in the following paragraphs, only the "services tier" and "domain tier" are directly considered in the process described in this document, with the most attention given to the services tier. The other tiers have their own delivery strategies, and those strategies are typically not service-oriented.

Presentation Tier

The presentation tier presents the informational content to consumers (clients).

Workspace Tier

The workspace tier provides conversational context, including personalization, and can optionally entail transactional and security contexts.

Services Tier

The services tier provides a contractual and consistent point of entry. The services tier is divided into architectural "layers," as described in The Concept of Service Layers.

Domain Tier

The domain tier provides domain-specific facilities and context. In particular, it provides a domain model of business objects.