Not sure why it matters but seems pretty straightforward to me:
Support is someone else helping along the way. Most common examples is carrying gear or being there to address issues that come up during the ride.
Unsupported is not having that support.
Whether you cook your meals or sleep in a motel or heaven forbid filter water from a stream, doesn't make a difference.
Yep. If I use a toilet at a c-store instead of always going au natural am I doing a supported tour?