Screwdrivers generally consist of a handle, a shaft, and a tip. The tip is the thing that is usually the differentiator. Here's a WIkipedia article on screwdrivers
Wikipedia has a nice article on types of screws.
i3 Detroit Tools
Here are the types of screwdrivers you will find in the shop:
What Screwdrivers are Not
They are not prybars