Open shape
320033
G is the G major chord. Its notes are G, B and D. A clear, stable sound. A natural home chord in a major key.
320033
320003
355433
x-10-12-12-12-10
Numbers show frets from the low E string to the high e string; x means don't play that string.
G is the I chord in G major, the IV chord in D major and the V chord in C major. That makes it a natural fit in songs written in those keys.
Every G, B and D on the first 12 frets. The filled dots are the root, G. Build your own shape from any nearby group.
Other G chords
Other major chords