A service task (henceforth called task in this document) denotes a single functionality that can be executed in a BPMN workflow like transcoding, XSL transformation, etc. Tasks require a task contract which contains the input and output parameters of the task and optional message boundary events (interrupting and non-interrupting) sent by the task. A task contract defines the interface between the workflow and the task and can be seen and selected in the VidiFlow Workflow Designer to model a BPMN workflow.
Tasks and their contacts use a semantic versioning scheme with major and minor version where breaking changes require a new major version and non-breaking changes are reflected in the minor version.
Try to keep a task's functionality as simple as possible, e.g. moving and copying a file should be two different tasks.
For further information about other types of tasks and their contracts refer to the VidiFlow Integration Guide.