Moochdocking is a slang term that means parking for free on property owned by someone you know and connecting to or using their utilities and facilities. It also includes parking on the street adjacent to the property. A related term is driveway surfing, in reference to the term couch surfing, where you sleep on someone's couch when visiting.
If you are a property owner, allowing moochdocking is one way you can help people who live in their vehicles. You can also rent your property using a service like Vanly.