This book covers topics which, to some degree, overlap. In the case of Chord Inversions and Chord Notes they also share one characteristic. That is the basic explanation of what they are is pretty straight forward, but in both cases the effect and implications on your keyboard playing are very substantial
and far reaching.
 
The third topic (Ornaments) is a smaller topic, not really worth a book on it's own, but worth discussing and is linked to the use of Chord Notes so this seems a logical place to present these ideas.
 
Chords are very powerful and when you have a good understanding of their inversions and the notes that make up chords you can do MANY things to make melodies more interesting and creative. You can add right hand chords, begin
composing songs, use this chord knowledge as a basis for improvising, add 'fancy bits' to your right hand etc.
 
All of these topics are about embellishing your performance and how you can make a simple song more interesting.