Condominiums are a form of real estate ownership where each homeowner owns the interior of their individual unit and shares in the ownership of common areas with other homeowners. Examples of common areas include hallways, entries, roof, siding, etc.
Typically, condominium units share walls with other units, though that isn’t a requirement. The biggest difference in condominiums is that the ownership of the plot of land is shared by the entire group of homeowners.
Condominiums are governed by a Homeowners Association (HOA) that collects dues to maintain, repair and improve common areas.