Retrofitting a minivan into a camper is called a conversion. There are several types of conversion vans that range from those featuring basic sleeping essentials to some that offer full-sized showers. Additionally, there are car companies that sell factory conversion vans.
The conversion process generally requires knowledge in plumbing and electrical work to install more complicated features such as solar-powered lighting or a sink. The process can also take several months depending on the condition of the vehicle.
Conversion vans are generally preferred for use in shorter trips, as opposed to larger recreational vehicles, due to their fuel economy. There are also companies, such as Escape Campervans, that rent out conversion vans fully equipped with all the essentials required to sleep outdoors.