CoachA net of a solid is a flat drawing of all its faces, attached along edges, that folds up into the solid — the solid unwrapped like a cardboard box flattened for recycling.
Examples
Example 35.4 (Reading a net)
On a die, opposite faces add up to . On a net, opposite faces are the ones separated by exactly one square in a row (or around a corner) — not the neighbors! Marking the pairs on the net before folding is a great exercise in seeing space flat.