The answer is â€œit dependsâ€.
A condominium is a dwelling type where you own your respective unit (usually from the drywall/plaster inward), and you also own a share of ownership in the common elements of the entire development.
Examples of common elements you might find: Pools, picnic areas, tennis courts, lobby, common walls and utility elements, concierge service, security office, parking garage, tennis courts, etc.
A townhouse â€“ which is an architectural style â€“ can be attached or adjoining other homes and is sometimes also a Fee Simple home. In a Fee Simple townhouse you own the entire structure, the land, the sky above it etc, but you will have joint ownership and maintenance obligations of a common party wall and possibly other elements like a common roof depending on the structure. You will usually have a pro-rata shore of ownership in the common area and elements of the community.
To add to the confusion, a townhouse can also be a condominium.
The short answer is all the owners of the condominiums own it in common and govern their ownership through their homeowner's association. In essence, you can think of the Homeowners Association as the owner of the land.