[hb]

I guess I've missed the deviance in these chords every since I started playing over 2 years ago and would like some help in identifying the difference in the structure of these chords. I had always thought that if a chord was, say a G, it was really a G major chord. But after looking, I see that there is a difference between a G7 and a G-major 7th. I guess I had always thought that when you see a G7, it was just short for Gmaj7th, but I guess I'm wrong. Can someone elaborate?
Thanks in advance,
hb