[ubercow13]

Where can I read about the true definition of virtualization?

[waon]

If you really want a formal definition, you could read this:

https://profsandhu.com/cs6393_s14/popek-goldberg-1974.pdf

Though some details may arguably be outdated, the general concept applies.

[ubercow13]

Thanks, the first section is pretty simple and covers it well.