A most basic question here guys; actually embarrassed to ask. I'm 2 years into playing; own a capo but have never used it. I can play melodies along with Youtube videos in each of the 5 pentatonic positions (modes) and transition fluidly between all 5 positions. My chord playing is still up in the open position and am currently working on learning chord inversions up and down the neck. I can usually nail down the key of a song by ear in 30 seconds or less (one notable exception lol...Marshall Tucker's "Cant You See"....G or D?) I've been doodling along to Zac Brown's "My Old Man"; clearly a song in the key of E. I go to the Ultimate Guitar website to check myself along with chord progressions and it's showing a 5 star version with the chords C Am F G with a capo on fret #4. I'm not understanding this; are these actual chords being played under the capo or chord shapes? My logic says a capo only changes open string notes, not fretted notes yes/no? Appreciate any help.