A special use permit, also called a conditional use permit, allows a parcel to be used in a manner it is not zoned for, but the ordinance must also authorize officials to grant permission for this specific use.
A nonconforming use is a pre-existing use that does not conform to the zoning ordinance but is grandfathered in.
This prevents the community from dictating what a private individual can do with his land.
However, nonconforming uses cannot be expanded. This is to encourage the landowner to move to a properly zoned area and to promote the ultimate elimination of nonconforming uses.