I will tell you that there are "open" chords....meaning you hold your fingers on the 3 triad notes ( or some 4 notes shords ) and strum all 6 stings...so other then than the 3 in the triad...the rest are open
if you look on a chord chart.....it shows you strum all 6...there will be O's above the stings that are not being held down with a finger..meaning that it is an open string...in a lot of the jazz chords I am learning and play there are little x's over the strings that are not to be played ....if you do it just sounds wrong and icky...it is more difficult to play these chords since you cant just strum away..you have to pay attention and only oick and strum what is in the chord
but I know there is a muchhhhh more technical response and im sure it will come along real soon
but look up open chords...