Dan,
In ActionComplete actions, waits, projects, and ideas are different types of tasks. Actions are active atomic tasks (actionable items), waits are delegated tasks, projects are composites that contain subordinate tasks (actions and waits), and ideas are deferred tasks you are decided to not act upon right away. All types of tasks exist within a context - or several contexts - defined by metadata (tags, people, and places). Tags are by far the most frequently used context markers. They can be anything that makes sense to you and meaningfully splits your tasks into manageable buckets.
Kind regards,
Borys Burnayev
ActionComplete
Your Streamlined GTD Toolkit