Orchestration is the harmonization and connection of different protocols and processes. It can be software that needs to be harmonized with each other, as in Software Defined Networking( SDN), to combine services of a service-orientedarchitecture( SOA), or to optimally connect individual application programs of a business process with different flow sequences.
Through orchestration, composite web services can be defined and multiple existing web services can be combined into a reusable business process.
The orchestration infrastructure, which is comparable to the control bus of a Service Oriented Architecture (SOA), controls the content, context and control information of the distributed business processes, whereby the orchestration ensures the interaction of the application data and the data stocks. For application components to interoperate, they must provide interfaces via Web Services Description Language(WSDL).
Orchestration tools can be used to aggregate, integrate, and nest Web services. Furthermore, the execution of the web services can be defined; whether sequential, parallel or time-dependent.