whe working on UV´s imagin that you jus Unwarp the texture from for example the face of some one, imagine how does it´ll look,...all pulled form the sides! so i can explin you leater oyu can...

in Mastering Maya COmplete 2 in page 236 you will learn about it
V is refering to the Vertical side and U reffers to the Horizontal side But you can allways rotate or modify their points on the UV...

let me check on my book lets see....

U, V and W are like X Y and Z in certain way but they are inside the geometry...

Hello?

are u on line pal?