What is SOA?
SOA is the acronym for Service Oriented Architecture. As it has come to be known, SOA is an architectural design pattern by which several guiding principles determine the nature of the design. Basically, SOA states that every component of a system should be a service, and the system should be composed of several loosely-coupled services. A service here means a unit of a program that serves a business process. Loosely-coupled here means that these services should be independent of each other so that changing one of them should not affect any other services.
SOA is neither a specific technology nor a specific language. It is just a blueprint or a system design approach. It is an architectural model that aims to enhance the efficiency, agility, and productivity of an enterprise system. The key concepts of SOA are services, high interoperability, and loose coupling.