Out-building, also referred to as an outbuilding, is a small or secondary structure that is typically located outside of the main building. It may serve a variety of purposes, such as storage, workshops, garages, or guest houses. There are several synonyms that can be used in place of out-building, including annex, extension, shed, barn, workshop, and outhouse. Annex typically refers to an additional part of a building, while extension implies a part that extends from the main building. A shed is a simple, single-story structure used for storage or as a workshop. A barn is a larger structure that is typically used for the storage of agricultural equipment. Meanwhile, an outhouse may refer to a small building that houses a toilet.