A barn is an agricultural building mainly positioned on farms and employed for numerous purposes, particularly for the housing of livestock and storeroom of crops. Additionally, barns may be utilized for equipment storage, as an enclosed workplace, such as threshing. The word barn is also employed to describe buildings used for purposes such as a tobacco barn or dairy barn.
In older style barns, the upper area was employed to store up hay and sometimes grain. This is called the mow or the hayloft. A large door at the top of the ends of the barn could be brought in so that hay could be put in the loft. The hay was lifted into the barn by a system containing pulleys and a trolley that ran along a track fastened to the top ridge of the barn. Trap doors in the floor enabled animal feed to be dropped into the mangers for the animals.
In New England it is general to find barns attached to the main farmhouse (connected farm architecture), letting for chores to be done while sheltering the worker from the weather. In the middle of the twentieth century the large broad roof of barns were sometimes painted with slogans in the United States. Most common of these were the 900 barns painted with posters for Rock City.