Ask most people why mobile homes are now called manufactured homes and they might tell you that it was created by the industry to try to make it sound more appealing since some have placed a negative connotation on mobile homes and the accompanying trailer park.
Yet the history of the mobile home is one that started after World War II when housing was needed. In the late 70's the government stepped in to make sure that certain standards existed in building mobile homes and then in the early 80's after the industry and the government started using the term "manufactured" home things went from there. Now, most parks call themselves "manufactured home communities" instead of trailer park. The actual construction features have changed where the image of a metal roofed narrow home is now one that can be set on a foundation or even with a basement with a traditional shingle style roof when the home is placed on it's own lot.
This also impacts the prices but in many cases a manufactured home is less expensive than a home built on site.