Expanded “Grating”, the width of the sheet is parallel to the short way of the diamond opening, the length is parallel to the long way of the diamond opening.

Expanded “Catwalk”, the opposite is true – the short way of the diamond runs parallel to the length of the sheet (typically 10 foot) and the long way of the diamond/opening runs the short dimension of the sheet. Catwalk is structurally stronger because the long way of the diamond runs across the shorter supported span.