Guitar chords are the lifeblood of all guitar music. Without getting too technical, chords are just the combination of notes. Different combinations play various roles in a song.
Chords are usually combined into a “progression” to move a song along a musical path. As the chords progress through a song, it creates the tension and resolution that makes up the heart of a musical communication.
That interplay between tension and resolution creates various emotions in the listener. Understanding how this communication works is the difference between moving a listener and moving from good music to great music.