Don't be afraid! In this video we walk through what exactly app registrations, enterprise apps and service principals are without really talking that much about Azure AD :-)
Whiteboard image on my random stuff GitHub repo at https://github.com/johnthebrit/RandomStuff/blob/master/AzureADAppRegandSPWhiteboardJune2020.png.
0:50 - INTRO
3:40 - OAUTH2 INTRO
8:15 - USER CONSENT SETTINGS IN AZURE
12:10 - CONFIDENTIAL AND PUBLIC CLIENT
13:40 - GETTING THE TOKENS
20:00 - AZURE AD APP REGISTRATION
25:32 - WHAT IS SERVICE PRINCIPAL
26:52 - ENTERPRISE APPS
28:30 - MULTI-TENANT APPS
31:40 - SUMMARY