The class B motorhome sometimes called a van conversion, looks like a large custom van but is smaller than the class C Mottor home. Much like a class C, a van conversion generally has living quarters, a cooking facility, sleeping and bathroom accomodations. Larger van Class B RVs can be equal to or even larger than the class C, but look more like a van.
The class B rvs provides walk-thru access between the driving and living areas without having to exit the rv.