What is a gauze ?

[TuRkiSh ToKeR]

I consider myself a good bong maker and i see this gauze word going around on this bong forum and i dont know what it is so its bothering me. Its used for the bowl i think, but i have no idea what it is. Could someone please help me out, maybe take a pic or description. Thanks Peace.

[tweedle]

You just stick it in the bowl ad it stops any weed getting through