Service Oriented Architecture is a reference architecture that is based on services. This means that SOA is a specific structured approach, based on services.
If architecture is defined from the perspective of services, it is called "service-oriented" or SOA in short.
Service-orientation can be applied on all levels: business level (the breakfast example), information level (applications delivering services to realize business processes), and technology level (web services such as
OrderService, services provided by infrastructure such as storage or high-availability, and so on).
According to The Open Group, a global consortium that enables the achievement of business objectives through IT standards, SOA has ...