The terminology varies between Unity and AVP - which makes things a bit more complicated.

First of all - there are three types of applications you can create: windowed, bounded and unbounded.

Basically this means that you can spawn windows or volumes. These can be spawned in full space (taking over everything) or in shared space - running side by side with other applications - and then in passthrough or fully immersive space.
The easiest way to port an existing game is to jump into full space immersive - which basically makes it a full-screen VR app. 

The next part is control, and this is where the AVP is completely different from other VR/AR headsets - as most headsets have direct control, hand tracking and you move things (or with a controller), and indirect control, you look somewhere, pinch and then perform an action.

As we wanted to test hand tracking against other headsets, and also portability against other headsets, we decided to go for a direct approach rather than a "look and pinch" approach.
The masking of the hands (so you can see the real hands) is best in class in the AVP.
The Quest can only dream of this, the Magic Leap2 obviously has it built in as you can see your real hands - but the AVP's tracking is miles ahead. 

A note on indirect control. As it's based on eye and hand interaction, you need to get used to it, and also be aware that it's slow, as you tend to want to do things faster (especially in games), you need to look somewhere, then send the signal to your fingers to pinch, then look somewhere else and do something - your brain... usually wants to do things faster... and already wants to look at the next step... lets see if our brains will adapt to become slower... or if the technology will understand us faster.