Types of Lightning
Anvil Lightning - One of the most dangerous kinds of lightning, anvil lightning starts up at the top of the cloud and then travels down until it disperses at the bottom edges of the cloud or connects with a grounded object.
Ball Lightning - Some aren't even sure if this really exists. For more info, take a look at "Strange Phenomena" part of the site.
Bead Lightning - This is the left over parts of a discharge, that seem to "bead and disappear." Considered very rare.
Ribbon Lightning - Lightning bolts appear to "hang together," coming from a single point in the sky. This "hanging" look is the result of a bolt having several up and down strokes.
Sheet Lightning - is lightning that leaps between clouds. This usually happens in the inside of the cloud and is very common in a thunderstorm.
Staccato Lightning - is the same as Ribbon Lightning.
Streak Lightning - is the most common type of lightning next to sheet lightning. This often forms cloud-to-ground strikes.
For other types of lightning, take a look at the sites in the credits section.