What things are in the Essentials Kit but not the Player’s Handbook and Dungeon Master’s Guide?

The Essentials Kit was published on June 24th 2019 (available everywhere on September 3rd of the same year) and some of the rules in it are different from how they appear in the PHB (even post-errata). I’m wondering just how many of these there are and what they are as they may result in certain rules being overturned.

I’ve currently provided my own answer with the things that I have found, and welcome anybody to edit in other examples throughout the books. Note that I’m not looking for things that are missing from the Essentials Kit, but things that are only in the Essentials Kit.