Screwdriver Safety Tips
When using any tool, always wear safety glasses for eye protection.Screwdrivers should only be used for their intended purpose—driving or removing screws. Screwdrivers should never be used for prying, punching, chiseling, scoring or scraping While both slotted and cross-slotted screwdrivers will fit many fastener sizes, it is best to use screwdrivers of the proper sizes that fit snugly into the slot or recessed portion of the fastener head.
Plastic handles should be made of fire- and heat-resistant materials. If properly designed, they give excellent grip. Rubber or vinyl is often used as a non-slip or insulating cover on plastic handles.
Typical screwdriver handles will not insulate the user from electric current.
It is time to discard the tool when the handle of a screwdriver becomes worn or breaks, if the tip is damaged or if the shaft is bent.
Screwdriver slippage can cause injury. Never hold the piece you’re working on in your hand while driving or loosening screws or bolts. Place it on a work surface and use a vice or a clamp to hold the material, whenever possible.
Never use pliers for added turning leverage on the shank of a screwdriver. However, a wrench may be used on square-shank drivers.
Never carry a screwdriver in your pocket.
Standard Slotted Tip Screwdriver For driving and removing standard, slotted screws
Slots generally range in size from 1/6” to 1/4”.
Tip is flared at shoulder of blade so it is wider than the driver bar.
Blades should not taper too sharply from the tip, because an improperly tapered tip has a tendency to rise out of the screw slot.
Can have a square or round shank.
Cabinet Slotted Tip Screwdriver
Similar to standard slotted, but tip is straight and has no flare.
For use with small screws and countersinking screws where regular tips with a flare would mar the wood or material on the side
Phillips™ Tip Screwdriver
Used on cross-slotted screw heads with modified U-shaped slots of uniform width.
Sizes range from 0 to 4, with 0 being the smallest.
Similar tip configurations include Frearson tips that have cross slots that are V-shaped slots with tapered sides, and Pizidriv® with additional, smaller slots at 45-degree angles to the main cross slots. 
Star (Torx™) Tip Screwdriver
Designed for use with star head screws and bolts to reduce slippage.
Tips have six lobular drive surfaces to provide additional contact surface with the screw head.
Vertical sides transmit torque perpendicularly to the driven element so there is no slipping or cam-out. 
Square Tip (Robertson) Screwdriver
Have square tipped heads to help grip the screw on all four sides to provide more torque.
Range in sizes from 0 to 3 and jumbo.
Popular with decking projects
Hex Nut Driver
Similar to a screwdriver, but has a tip like a wrench socket.
Used mainly on small hex nuts and in confined areas such as electronic equipment, car ignitions and plumbing jobs.
Available in several sizes and styles, with a fixed-size or variable-size “socket” at the end to adjust to various nut sizes. 
Offset Screwdriver
Designed for removing and inserting screws in places where it is impossible to use a straight shank screwdriver.
Available in two- or four-blade varieties, with one end slotted and one end Phillips
Some models available with reversible ratcheting mechanism to turn screw tip and magnetized tips to guide screws into holes or otherwise inaccessible areas.
Others have split-points that can be expanded in width to fill the screw slot and hold screws when guiding into inaccessible areas. A spring clamp that fits over the screw head, holding the bit in the slot, serves a similar purpose. 
Ratcheting Screwdriver
Features a reversible ratchet mechanism in the handle that eliminates the need to grip and re-grip during the driving process.
Usually comes with interchangeable tip.

Spiral-Ratchet Screwdriver
Also called Yankee Screwdriver or Yankee Push Drill.
Drills and removes screws using a ratchet mechanism similar to a push-pull drill, with driving action provided by pushing straight down on the handle.
It has an adjustable chuck to permit interchanging different size driver tips and drill points. 
Clutch-Head Screwdriver
Tips have four points of contact.
It locks into the screw head when turned counter-clock-wise.
The driver is unlocked by turning it in the opposite direction.
Because of the many contact points, the tip will not damage the screw head under high torque situations.
Hex (Hexagonal) Tip Screwdriver
Also called a hex key or hex wrench.
It is used to tighten socket set (hex head) screws and usually comes in sets.
Some hex sets are attached to and fold into a metal carrying case.
Multi-Bit Screwdriver
Allows the user to have a number of different types of tips in one tool.
Some models store the interchangeable tips in a self-contained unit.
Jeweler's Screwdriver
Has a rotating head that is held by the forefinger to steady the screwdriver while the thumb and middle finger turn the screwdriver to remove or install small screws.
Mainly used by jewelers and hobbyists and others who often work with very small screws.
Generally manufactured in sizes ranging from .025” to .1”.
Usually available in sets with Phillips and slotted tips.
Courtsey of NRHA.org