Forty years ago these homes were called trailers, always had wheels, narrow widths and felt like you were permanently camping in little busses. Nowadays these homes are 12 to 40 feet wide and 30 to 70 feet long and loaded with amenities. They're not really mobile anymore either unless you consider the trip from the factory to the site in the mobile home park. Once they are set up it takes a professional mover to move them again at a substantial cost. What sets a mobile home apart from modular housing is that modular homes are put on foundations and treated like site built homes as far as local building officials are concerned, meeting local building codes.
Modular units are delivered by flat bed trucks, mobile homes arrive with their wheels on.
A mobile home comes complete with a roof and floor and needs only to be set on supports and anchored down. They are built in accordance to the standards of the federal government's Department of Housing and Urban Development. HUD requires a label showing compliance with their regulations. In this snow free state the roof must have a load potential of 20 pounds per square foot and hurricane resistive requirements of 25 p.s.f. A State of Florida law requires that all mobile homes must have tie downs and smoke detectors.