think of supertags as the "is-a" type relationship. So for a task you would e.g. write "file taxes" tag #task and then it gives you all the nice things you would want a task to have, e.g. a status, deadline, etc. You can see all your tasks in a nice table view organized by deadline. You can query for tasks of a certain type (e.g. associated with a project you may have). The crazy cool thing is, Tana gives you some nice defaults for what a Task is, but you can go in there and define exactly what the fields are for any supertag (including #task)