SOA: the basics. What it is. What it is not. SOA: the false, the ideal, the real. False: SOA equals web services. SOA equals distributed services. Ideal: SOA cleanly partitions and consistently represent business services.
What it is.
What it is not.
SOA equals distributed services.
Technical architecture that adheres to and supports the principles of service orientation.
SOA is a magic global solution to general interoperability.
Source: Service-Oriented Architecture, Thomas Erl