SOA - A Loosely Coupled Architecture
Service Oriented Architecture (SOA) is an architectue that is designed based on loose coupling with interacting software agents.
SOA is different from object oriented programming. It does not bind data and processing together.
In SOA's, a "service" is a unit of work done by the service provider. The service delivers specific end results for a service consumer.
Both the service provider and consumer are defined roles executed by software agents on behalf of the agents' owner.
The huge differentiator is that SOA is a loosely coupled architecture in the manner in which it interacts with software agents.
This provides a flexible, adaptive and scaleable architecture.