It is stuff about which something needs to be done; that is, it is something that you can and want to start moving on towards its conclusion. You are already able to act upon it by defining a viable and concrete next action.

In GTD, actionable items are contained in the following lists:

• Calendar, for items that must be done on a specific day or time.
• Next Actions, for everything that you need to do as soon as possible.
• Waiting For, for all the things you have delegated to someone else.