All music is made up of the fundamental elements of Rhythm, Harmony and Melody.  Guitar players often perform a role of playing "rhythm" or "accompaniment" which embodies two of the essential elements of music making being Rhythm and Harmony while a vocalist or additional instrument carries the melody.  When the Guitar is played as a solo instrument the 3rd element of melody is played by the guitarist as well and this is referred to as "Chord Melody" style.   This style of playing may be performed either in a finger style or in a plectrum style but no matter the technique the ultimate goal is to use the guitar as a solo instrument by learning to build solo arrangements.   This chord melody style requires a strong functional understanding of how harmony works in supporting the melody line, this is also covered in this series.