Block is an item on Bad Piggies they appear in all levels and they can either be metal or wooden. Items or pigs can be placed in or out from them
The main difference between the 2 boxes are that the metal is more durabile. If a box recieves enough force, it can
1. Break off of other parts
2. Release the object it is holding.
Boxes can recieve too much force by moving too fast and properllers can break off by flying to fast.