1) Wood product 
Shiplap is a type of wooden board used commonly in the construction of barns, sheds, outbuildings and inexpensive or seasonal homes. It is either rough-sawn 1` or milled 3/4` pine or similarly inexpensive wood between 3` and 10` wide with a 3/8` - 1/2` rabbet on opposite sides of each end. The rabbet allows the boards to overlap in this area...
Wood panels on the sides of buildings, barns and other structures.
You’ve probably seen shiplaps everywhere, but may have referred to them as wood panels. Shiplaps are a type of inexpensive wooden board or panels fixed onto the sides of barns, sheds, and homes.