A Dutch barn is a roof supported on pillars with no walls. It is used for hay or straw storage only, since animals or grain need better protection. The name comes from the shape of the roof, which is similar to that of Dutch houses.
The word barn covers a large number of different structures, fulfilling several different functions - strong grain, fodder, machinery and animals. Older barns also combined a threshing floor where the ears of grain were beaten out by flails.
Barns are built big, with as few internal pillars as possible, so that full use can be made of the space, and carts, trailers and machinery can pass in and out. Often they have lofts where hay is stored.