This file explains the basics of what I learned about USB-C PD to help development engineers on their projects. I'm not an english mother-language speaker, so here I leave my apology for any mistakes.
Again, this docs relates what I learned. I'm not an expert on USB-C PD.
The USB-C standard came with far more features than the previous standards. The thing that most catches the attention of common users is that you don't need to be aware of cable orientation (the connector is symmetrical).