Lightning is a huge electrical discharge that results from the rising and sinking air motions that occur in thunderstorms. Lightning can be either cloud-to-cloud or cloud-to-ground and is accompanied by thunder. Lighting also has different appearances.
Staccato lightning is a cloud-to-ground lightning strike that is a short-duration stroke that often, but not always, appears as a single very bright flash and often has considerable branching. Forked lightning is a name, not in formal usage, for cloud-to-ground lightning that exhibits branching of its path. Ribbon lightning occurs in thunderstorms with high cross winds and multiple strokes. The wind will blow each successive stroke slightly to one side of the previous stroke, causing a ribbon appearance. Bead lightning is a type of cloud-to-ground lightning which appears to break up into a string of short, bright sections. It is relatively rare.
Heat lightning is a common name for a lightning flash that appears to produce no discernible thunder because it occurs too far away for the thunder to be heard. The sound waves dissipate before they reach the observer.
During the past two decades scientists have discovered and confirmed the existence of lightning that shoots upward into the upper atmosphere from thunderstorms. Red sprites and elves occur over cloud-to-ground lightning bolts and can extend to near the top of the atmosphere. They are too quick and weak to be seen by the naked eye. Blue jets, in contrast, are limited to the stratosphere and last long enough to be seen by pilots. Much is still not understood about these electrical phenomena.