Let’s start with Broadcast AR: With the “mirror” shape, the user looks at a screen and sees himself/herself, as well as the Augmented Reality model. Both the user and the digital model are visible on the same screen.
Screen AR: The AR model is displayed on the “lens” model. This screen is located between the user and the AR model. IA smartphone screen or AR glasses (Hololens/Magic Leap) may be used as a screen but these are AR apps that you can experience on your smartphone.
Projected AR: The main feature of spatial Augmented Reality combines an object with a physical object. The most famous is Projection Mapping (or 3D Video mapping).
There are already many projections on buildings and other objects to utilize.
Finally: Holograms – a holographic projection actually falls under Projected AR. As an example the projection of an artist on a stage (done with “gauze cloth”) or a reflection of a glass screen (Hologram display/Holobox).