Fretboard Mechanics refers to the way the musical language translates to the idiosyncracies and design of the guitar fretboard.  For example on the guitar most pitches can be played in several different places, this isn’t possible on the piano for example.  This fact alone creates many different challenges and possibilities that are individual to the guitar.  The study of fretboard mechanics amounts to a separate study of how the design of the instrument works and how this functionality relates to expressing musical thought.