Mobile home refers to any home constructed entirely in a factory, fixed on a permanent steel chassis. It's towable, in whole or in sections, and can be moved to a site. These structures are not permanently attached to a foundation.

However, there is an important technical definition of a mobile home. H.U.D. (the U.S. Department of Housing and Urban Development) uses the term mobile home for manufactured housing built before June 15, 1976. Those built after that date are called manufactured homes. By this definition (pre-1976) does not meet H.U.D. standards and isn't compliant with H.U.D. safety codes. It may still meet state housing codes and be perfectly safe to occupy, but it will be difficult to finance without H.U.D. certification tags. FHA loans won't be granted and many other lenders follow FHA standards. Also, in many states, manufactured housing without H.U.D. tags can't legally be towed to another site, which has an impact on their future saleability.