Usually a lot is in a park and you pay rent for the lot. Land would be land you purchase that has a mobile home on it. The problem you may run into with land is the appraisal. If the Mobile home has not had the title purged it is not considered part of the land but personal property ( Not Real Estate ).
Not only does the title need to be purged but to do that the mobile would most likely have to be on a foundation.
If the title is not purged then the appraisal would be on the land only.
To buy a mobile home that is in a park is pretty much the same as buying a car since the home is considered the same as a trailer and has a motor vehicle title not a Real Estate Title.