Farmhouse is a general term for the main house of a farm. It is a type of building or house which serves a residential purpose in a rural or agricultural setting. Most often, the surrounding environment will be a farm. Many farm houses are shaped like a T. The perpendicular section is referred to as the ell.
These buildings tend to be more pragmatic than aesthetic. Sometimes a farmhouse may refer to a building design style, or a building's former purpose. This may occur when the farming area has been developed for other purposes, but the building itself still stands. Architectural styles vary, but very often they are of Cape Cod design. In general styles vary from region to region, but more often the style is simplistic so to serve the needs (and the budget) of the owners.