Wet fly hooks are similar to dry fly hooks except they are usually heavier. Hook bends and shank lengths vary in these hooks depending on their designed use. Nymph hooks vary in design more than any other type. Some are designed to tie scuds , others lend their design to stonefly nymphs and some are just good hooks for common nymphs like mayflies and caddis larva. Try to select a nymph hook with a shape similar to the natural nymph you wish to imitate.
Streamers usually imitate minnows, leaches, crayfish or other swimming critters.
Their hooks are usually longer than the rest and often have specific bends to accommodate the swimming pattern of the subject being copied. Some hooks are designed for use in poppers for bass and panfish. These have a hump in the shank to prevent any turning of the popper body. As you can see, there are a lot of hooks out there. They each have their designed uses.