The Subs can best be described as a “flow-in-block” function or a sub-process. Subs are flows without intents and they are particularly useful when you have a sequence of elements, blocks or flows that you use frequently. Simply by creating a Sub you can re-use this sequence without having the need to rebuild them.
When creating and editing a Sub, you are requested to enter different details:
You need a name for your Sub and possibly you can define a description, input and output variables. These inputs and outputs work similar to any other Function. Once you have created the Sub, you are able to use it as a building block in a bigger function. Furthermore, Subs can be tested like Functions by clicking on the 'Test Sub Flow' button. Finally, the 'Show Usage' button indicates all the flows where a specific flow is incorporated.