Dry flies mainly float on top of the water and immitate fully hatched insects. Wet flies are submersible and immitate insects which have not fully developed. The trick to fly fishing in general is to match your fly to what the fish are feeding on. If you were to take a sein in the river and stretch it across, you would probably freak out at what you would find. Insects of all types and stages in the development process. They look like nothing you've ever seen before. So when we talk about a dry/dropper rig, basically you tie on a dry fly as the point or indicator. You then tie a section of line on the dry hook and drop off a wet fly/midge/baetis/nymph. You effectively use the first fly as a bobber for the submerged fly..
Phisherman..
Agreed on the hoppers. Those things rock in August. Get a good drift along the bank and you better hang on cause the hopper will be jumping

. I personally like the Dave's hopper and foam bodies.
Do you ever fish any foam beetles or ants?