You learn the sound and feel of every interval: Unison, Minor Second (the chromatic crunch), Major Third (the happy skip), and the Perfect Fifth (the power chord). Each interval gets a fretboard diagram and a "sound association" song (e.g., "Jaws" for the Minor Second).
The VK Guitar Book favors a pragmatic, encouraging voice: prioritize musicality and feel over perfection, and learn by playing real music. It avoids overwhelming theoretical depth; instead it shows how simple theoretical concepts unlock creative options on the instrument. vk guitar book