What is a guitar tab?

Tablature is a way of reading music on Guitars e.g. Top E ------------0 (0 = the open string so 1 would be the first fret) B------------------0----------- G-------------------------0---------------- D---------------------------------0------------------- A------------------------------------------0---------------------- Bottom E---------------------------------------------------0----------------------- this is in an order so you would play the top E first then B then G and so on and so forth. Also go onto www.ultimateguitar.com for more of this stuff hope this helps