What is a Workflow?
When we talk about sending the "right message to the right patient at the right time," workflows fulfill the "right time" component.
Workflows allow you to select a List, a piece of Content, and a triggering event. A triggering event is usually time-based (i.e. one day after initial evaluation) and is what causes the content to be sent to the patient list.
Workflows are the last component you set up in Reach because you'll need to tie a pre-existing list and content item to the workflow during creation.