What are Root Notes in Blues Fingerpicking?

"Okay, so maybe you noticed, when we were doing that very simple arpeggiated fingerpicking, that the first beat of every measure is actually the low note in the chord. What we call that in music is the root note of the chord. And so, what that means is, is if you're playing a C chord, the root is of the low C of that chord, or it's, basically, the first note in a C scale that that chord is based on. So, the root of the C chord is the C, the root of an E chord is E and, etcetera. It's kind of elementary. But, musically, you want to play that root note kind of at the beginning of any fingerpicking sequence. So, if we go back to the "Blue Moon," every sort of chord starts with the root. So, if I'm going, right, so that's going C, A, F, G those are the actual chords I'm playing and that's actually the note that is being played as that low note, that root, with each of those picking sequences. Okay? So, that's really what your thumb is doing when you're fingerpicking. Your thumb is playing the root notes of the chords that you're fingering with your left hand. So, but, the thing with the root notes is, when you're playing a chord on a guitar, that root might be on the low E string, it might be on the A string or it might be on the D string. And so that's why for fingerpicking style, I like to kind of dedicate my thumb to all three of those strings, because the root could, depending on the chord, could kind of be in any one of them. So, for example, for an E chord, the root is on the low E, so if I was to arpeggiate that, you know, I would pluck the low E with my thumb. But, for an A, the root is on the A string, which is one string up. Okay? Well, I still want to use my thumb for that because, kind of one of the basics of fingerpicking is that you kind of dedicate your thumb to the low notes. So, for an A, the root's here. So, just kind of keep that in mind as you're learning to fingerpick, is where is the root of the chord, what note is that, and you might want to have your thumb dedicated to those roots."