What is the Item Editor?
The Item Editor is the primary mode in the Author API for the creation of new Items, Questions and Features. It provides a simple, user friendly UI and UX to create new item content.
It encompasses the Item Edit screen, including settings to control item layout, tagging and dynamic content tables (if enabled). It provides an edit screen to allow you to add or change any questions or features, and a preview screen to allow you to play around with the item you've created as a student would.
You can configure what options are available to your end user, and can optionally skip the user straight to the Question Editor, in cases where you intend to only have one question per item, or have more prescriptive layouts.
What is the Question Editor?
On clicking the blue plus symbol, or using the navigate() public method to create a new question, you're presenting with the Question Editor, which allows you to add new questions or features to an item.
In this view, you can click in to add any question and feature to an item, and you can tailor this view to show only the question types, or custom question templates, you may wish.