A Gizmo is an advanced piece of media or interactivity placed on the page. At a technical level, it is a web component, but to your users and content readers it's an advanced piece of functionality helping them complete a task. Maybe they want to embed an article from Wikipedia, or create a gorgeous, responsive video. How would they do that without advanced code knowledge?
Gizmo's ensure that your users have a consistent visual presentation and authoring experience across a myriad of complex functionality. Any web component can be wired to support HAX.
An App adds remote data capabilities to HAX. Want to search Youtube without leaving your editing experience? Hax Apps are the way to do that. Apps show up for users under the Find menu and while we provide definitions for talking to commonly used APIs, it can be modified to connect to almost anything.