Is there any kind of authoritative guide to Apple's Volume Purchase Program, Device Enrollment Program, and Mobile Device Management? I'm fairly new to the whole world of Apple and macOS. As I'm currently writing my thesis about the possible enrollment of macOS devices via Device Enrollment Program (DEP) (in connecting with some other stuff), I searched the Web, books and the Apple's Developer documentation, but I have not found a reliable guide on how to use Volume Purchase Program (VPP) and DEP (or at least a "quotable" description), only the handbook for ABM (which is pretty good, but does not answer all my questions).

Am I just blind or are there some "hidden" gems that i seem to overlook? Maybe there is a guide in Apple Business Manager (ABM) directly, to which i don't have access - yet - ?
I'm sure if you'd searched the Web just with the keywords that you have listed, you'd get a lot of official resources right on the first page of the search results.

But nonetheless, here are some links to get you started:


Apple Deployment Programs - Volume Purchase Program Guide
Apple Deployment Programs - Device Enrollment Program Guide
Apple Deployment Reference - Mac
Apple Deployment Reference - iPhone and iPad
Mobile Device Management Settings
Apple Deployment Programs
Upgrade from Apple Deployment Programs
Volume Purchase Program
Apple Business Manager User Guide
Business Support
Getting Started Guide - Apple Business Manager
Upgrade your organization to Apple Business Manager