Thanks, billy and felix for answering j123's question. Felix, perhaps 'thousands' is pushing it a bit, but yes, a chord on a guitar is a pattern of notes that stretches the length of the fretboard and so long as you're twanging at least one of each required note, you're playing that chord. Once you can see that pattern easily, you can be all over the neck playing the same chord, or if you're playing melody, you can see all the strongest notes in one sweep.
PT teaches the easiest way I've ever come across to do just that. It does take practice, of course, as billy points out, but once you 'see' it, you'll see it for ever more, and the simple mind set can become
all you need to consciously follow, I know that's how it is for me now after years of doing it.