Updates are a snapshot of the status of your overarching goals/initiatives/projects. They have a state of On Target, At Risk and Off Target. They are meant for information only, not for discussion. If there is something specific you want to talk about in any of these goals/initiatives/projects (like something that is Off Target), you add them as a separate Discussion item. Updates roll forward on the agenda until deleted.
Discussions are the meat of your meeting! This is where you have the specific topics you want to cover in your meeting. Discussions have a state of Open, Closed, or Tabled. Open discussions remain on the agenda and roll forward automatically to subsequent agendas until marked as Done. A Discussion that is Tabled also remains on the agenda but is moved to the bottom of the Discussion list until it is either marked as an Open or as Done.