Lets start basic. Lug nuts hold the wheel to the vehicle. Lug bolts do the same thing, but they screw into the rotor, where as lug nuts screw on to the stems already in the rotor. Most US and Japanesse cars use lug nuts. Europeon cars tend to use bolts.

Lug nuts are measured in diameter and threads per inch/millimeter. The number you see on them is usually a 12x1.5, which means it is 12millimeters in diameter for the hole/stem. The 1.5 is not the length, but the threads crest distance in millimeters. On older cars it may be a 1/2 inch nut with a dash 20, which is 1/2 hole and 20 threads per inch. Most modern cars are in metric.

Length or a Height is not really measured. Standard lug nuts are about 1.5 inches tall. For trucks they are taller at 2 inches and usually are referred to as a Duplex.

Bolts are in two forms of seats. One is Ball Seat and the other is Cone seat. A Cone seat is an angle area that seats to the wheel. BMW is usually this way, where as Audi, Mercedes, and Volkwagen are a Ball Seat on the OE Wheels. Most aftermarket wheels that fit these vehicles are Cone Seat.

Honda is the only manufacturer we know of to use a Ball seat lug nut for the factory wheels. Toyota tends to use Mag Shank lug nuts on their trucks.

Mag Shank lug nuts are like a normal lug nut, but they have a short stem on them that goes into the wheel. This makes the wheel lug centric and reduces the chance of vibration at higher speeds. Mag shank lug nuts also have a flat bottom where they come in contact with the wheel.

Then there is also the ET Ultra style which has a cone seat, with a mag shank. These are usually used by cars in track events. They allow for the cone seat of the more common wheel and they have a short shank on them to make them lug centric.