I'm working on a project about virtualization (specifically hardware level and a little OS-level virtualization), when I started I thought it would be no problem, but the more I work on it, the more I realise how much stuff just doesn't seem to make sense. It probably doesn't help that I learnt the basics 1 to 2 years ago and am more or less shuffling through google results, finding articles and old forum posts about the topic, but I keep writing something that doesn't quite make sense, look it up, then go down another massive rabbit hole of indirectly confirming and contradicting information. So I'm just going to give this a go.
At first, I knew of the 2 types of hypervisors and the "3" basic types of virtualization: full virtualization, para-virtualization, and hardware-assisted virtualization.
But now I know (or am convinced at least), that there is full virtualization, which is in two categories, software-assisted (often referred to just as full virtualization?) and hardware-assisted. Software-assisted can only use a type 2 hypervisor, while hardware-assisted can be type 1 or 2, oh, and only full virtualization uses hypervisors (and they're actually called VMMs for type 2, not hypervisors at all).
Then, separate from full virtualization, is para-virtualization, which is based on hypervisors(?), but does not use a hypervisor(?). I'm not even confident if para-virtualization is bare-metal, hosted, both, or if it's something entirely different anymore.
There is also "hybrid virtualization" a combination of full and para-virtualization (somehow), which is a whole other can of worms that I've found down these rabbit holes. I'm still trying to wrap my head around the other 2 (3?), don't get me started on that one.
Lastly, there are containers (the OS-level virtualization kind (I think)), which are for some reason lumped together with the previous 4 (3?). I know they kind of do the same thing (end result), but it's on a different layer isn't it? why are they together?
If anybody can help explain these, or go over where and how I'm wrong, even in part, I would be very grateful, because my head starts hurting just trying to think about it at this point.