You can define is there is a / multiple list sources. In that case only collaborators inside the list will be inside the campaign.
You can also drag & drop actions inside your campaign.
Actions are done by the &shift platform, they are not triggered by collaborators decisions. You can add actions to adjust the collaborators points, change the campaigns or lists he's in, send an E-Mail. For each action, you can define the : name, action timing and your action parameters.
Decisions can also be drag & dropped in the campaign. Decisions are the result of a collaborator activity, they can end with a success if a collaborator does the activity or a failure if he doesnt after the timing defined in the attached failure actions.