Workflow is an automation workflow software which can run in the background, accessible by the system tray on Windows OS, and the menu bar in macOS.

When the full Workflow window is open, clicking the X close button will not shutdown the app and stop the workflows, instead it will place the app into the background, available in the system tray/menu bar:

To fully shutdown the app (and therefore pause all automation workflows), you need to click shutdown from the system tray/menu bar: