Coupe vs. Hardtop - differences??

At the risk of sounding stupid, can someone tell me what the differences are between a GTO coupe and a GTO hard top? I have been looking at pictures of both, and can't seem to figure out the differentiation.

I have been involved with Mustanges, and the coupes are the notchback style roof, the fastback style has the sloping pillars down to the back, and, of course the convertible is self-explanatory.

Thanks, in advance, for the education.

The coupe or post coupe has the post next to the door and the hardtop doesn't. Coupes are considered stonger and better for racing, but probably don't look as good.