>>64455
In guitar there are multiple "chord forms" like barre chords like >>64501 said, or power chords like >>64491 said. There are many many many variations. The jazz forms are common as well, which would be your major and minor 7ths, along with the dominant 7ths, 9ths, 13ths etc.
What Iv'e been trying to figure out is what chord are you playing in this picture. You are playing an F chord, D string form, with a C in the bass. Very similar to the F barre chord, but probably easier to hold and play. It looks similar to the C7 open form, which just happens to also be the dominant 5th chord of F. All you have to do is move your middle finger up one string, and move your pinky finger down one string and viola! You have 90 percent of popular music