[joelwilliamson]

The “board” in a boarding house is food. There can be other services as well, but food is definitely required to be a boarding house.

[SoftTalker]

Yes, the situation with shared common areas and private bedrooms individually leased is more typically called "single room occupancy" (SRO) and is often prohibited by local rental codes.

Where I live there is discussion about allowing it in some neighborhoods, with the requirement that the property owner is also resident in the house.