A service-oriented architecture (SOA) / web service application is a solution based on client-server architecture. A web service or SOA can be consumed by any client, only the exchange formats and technology are specific. As a result, many different systems can be clients, for example, M2M, IIoT, database, mobile client solutions, etc. These tools maximize the agility, interoperability and scalability of developments and systems.
An SOA is a model for interactive applications based on services. These services offer both strong internal consistency (through the use of a central exchange format, usually XML) and loose external coupling (through the use of an interoperable interface, usually a WS-* Web service).