What is the meaning of…
an area with non-permanent, less expensive homes
Years ago, trailer parks had a negative cultural association because they were often where lower income, transient (i.e., staying only for a short time) people lived. Because of this, some trailer parks were not very well-maintained.
To try and remove this negative association, the new (much nicer) trailers are called mobile homes.
Trailers now refers to holiday trailers, not non-permanent homes.
1. My co-worker recently moved to our city, and she and her husband moved into a mobile home so they won’t be rushed while they shop for a house. She is obviously embarrassed about not having a permanent home, and it is important to her that nobody says she lives in a trailer park.