Drafts is a new feature in Voca Quest Studio. Drafts will be auto-created when you begin to create activities but do not finish. This makes it easier for you to work on activities when you have time, instead of having to plan to do it all at once.
Your drafts bar is in Studio under the Edit/Delete Activity tab, it will initially be empty until your first draft is saved.
To create a draft, simply exit out of an activity you are creating. Then select it in your drafts and press Customise content to edit or complete. You can also select Delete activity here to delete the draft.