Greetings and salutations and stuff . . . Everything I know (or think I know) about playing guitar I have developed on my own, like a guy stranded on a desert island with only a guitar. And what I have learned is that I have no idea what I am really doing. I recently acquired a poster containing over 100 chords, however, it's only made matters worse. I have no idea what a chord really is. I have discovered what appears to be power chords in what a friend tells me is something called "drop d". I have no idea what any of this really means. I don't even know where I need to start. Any help that could be offered would be deeply appreciated. Is there any difference between a bar chord and a power chord? What is a chord? What am I doing? Please help me . . . . .

(Dream Theater, Metropolis Part 2: Scenes From A Memory . . . . . The most beautiful work of art I have ever discovered)