Orchestrator has a REST-based API that allows you to interact with workflows as well as a lot more. We will be exploring this in this chapter in more detail.
Orchestrator used to have a SOAP API but it was discontinued; however, the VMware document
vrealize-orchestrator-70-develop-web-services-guide.pdf
still contains a chapter on it. So don't be mislead. Orchestrator SOAP is gone.
The REST API, in my opinion, is better and easier to use, especially as we have the fabulous Swagger UI to go and play with it (see the recipe Accessing Orchestrator REST API in this chapter).
Orchestrator can be accessed in a lot of ways, but they all come down to using the REST API.