Watch the Week 4: Outlining Harmony Via Chord Tones online guitar lesson by Joe Pinnavaia from Guitar Soloing Essentials
Triads are the core of any chord such as major, minor, diminished, etc. The Focus here is to start out with learning the various shapes on the guitar and to start using them right away! Triads have been used by a lot of sax players and they are the best when it comes to superimposing them over chords. Another tool in your bag that can be used with improvising solos!