Is a fashion who was created back in the early 80's, which mainly was brought by the well known band X-Japan. Which was created back in the middle of the 80's, but diden't get it's major notice till the 90's when bands such as Glay , L'Arc-en-ciel and Kuroyume took up is style.
This style mainly concepts on the visual effect of the theme they pick. Which can be some what a feminine side(which is really popular in male Visual kei perspectiv), and many famous bands are in this perspectives. Mana from Malice Mizer is one known figure, which now days plays in Moi dix mois.
Tough most bands in this usally are males, but later years there to has been female bands such as Exist†trace. But to this most fans in this music is mainly girls. Best way to define this look is probly mostley by is make-up, hairstyles and there gothic cloths, pretty much filling up there naughty or bad characters.
Another thing whichs is quite common in this, is that if a group changes is record company they usally change style to fit in for the larger audience to.
Example bands to this: Miyavi, Versailles , X-japan & Glay.
Is the more happy version to the Visual Kei, much of it is pretty much cute subjects. It also contains alot of the most cutting edge fashion today as is main perspectiv and also by so is seen to be the most fashionable of the three.
Example bands to this: An Cafe, Panic Channel, SuG, LM.C & Ayabie.
Is pretty close to the visual kei and usally referred to it as is easier. But is basicly the metal version of rock. Is a bit more ruff in is ways and dark concepts. And the main concepts are pretty much black cloths, spikes, modern hairstyles and alot of dark make-up. Many compare them to goths of daily standards.
Example bands to this: MUCC, Sadie, Girugamesh & Dir en grey.
Well here was a little info about the diffrent kei's, But hope you like it even if is not much it should giva a little better understanding!
(And don't wanna bore you with to much with long facts and schematics.)