Chanel newbie question re styles

  1. I'm drooling over the gorgeous bags you've all posted but I'm a bit confused as to single flap and double flap. Could someone please explain so that when I make it to the Chanel boutique I don't sound like a complete fashion idiot.:shame:
    Also, I've noticed in the photos that some bags look like they have ONE opening on each side (top) for the strap, some appear to have TWO openings right next to each other on each side (top) for the straps, and some appear to have TWO openings one behind the other on each side (top) for the straps.
    I'm trying to figure out which is which.
    Thank you so much in advance!:smile: