Keyword Workflows allow people to text in to join a List and receive a series of automated message you've created:

​Automated Workflows are similar to Keyword Workflows, but rather than texting in with a Keyword to join, people will join based on which List they are in. Automated Workflows are tied to a List and they trigger at a specific time each week. When it triggers, anyone who has been added to that List since the last trigger will be entered into the Workflow. Automated Workflows are helpful for following up with new guests who filled out a paper connect card.