The five basic Major chord shapes
There are five basic Major chord shapes, from which many other chords can be derived. It sometimes requires a strech of imagination as well as fingers, but it is a useful system as it crops up everywhere. There is no deep reason or theory behind this. It is just an artifact of the tuning of the strings and the limitations of the human hand. It may be obvious but do remember that the shape name is not the chord name. The fretboard below shows these chord shapes as variants of the C Major chord. Press the buttons to see the chords. Note how one flows from the other and allows this Major chord to be played in 5 diffent positions up the fretboard.
The five derived Minor chords
A major chord contains the root, a Major 3rd and a Perfect 5th. Each of these notes can be duplicated. A minor chord is the same except it has a Minor 3rd, which is just a flattened 3rd. So, in the C Major chords above, the Major 3rd is E, so to create the minor we just need to replace this with Eb. And we get the following basic shapes.