This has been my definition:
Apartment: Can be owned or rented, shares a common entrance with other tenants.
Condo: Can be owned or rented, has a private entrance usually with a sidewalk leading to it, consists of 1 floor in a mutltiple-floor unit, ie: upstairs or downstairs units.
Townhouse: Can be owned or rented, has a private entrance usually with a sidewalk leading to it, typically consists of multiple floors in a multi-floor unit, ie: both upstairs and downstars are one unit.
... except that I am surprised when I do research. I find things like this:
Apartment: a room or set of rooms fitted especially with housekeeping facilities and usually leased as a dwelling
Condo: individual ownership of a unit in a multiunit structure (as an apartment building) or on land owned in common (as a town house complex)
Townhouse: a usually single-family house of two or sometimes three stories that is usually connected to a similar house by a common sidewall
.. elsehwere I find this:
"Another major difference between an apartment building and a condominium complex is that condominium associations have covenants, conditions and restrictions (CC&Rs), which govern everything from the elections of HOA officers to the allocation of parking spaces. Unlike the rules of an apartment building, CC&Rs are legally enforceable documents that apply to tenants as well as resident owners. "Tenants must abide by the CC&Rs and all the other rules and regulations, but the owner of the condominium is the ultimate responsible party. If the owners don't protect themselves, the tenant can cause problems and the owner ends up receiving notices from the association about rule violations," says Bupp. HOAs can—and do—impose fines if the CC&Rs or other rules are disobeyed. And those fines can be levied even if a tenant was responsible for the violation."
Yet I've seen CC&R's for apartment and townhouse owners. Hell, I had CC&R's for both the condo AND the townhouse that I used to own.
Elsewhere I've seen described that you can only RENT an apartment but that you can BUY a condo. But I grew up in a condo that you couldn't buy as part of a huge condo development, and I know of lots of APARTMENTS for SALE in NYC.
Still further, I found one source that actually calls them all the same thing, that is.. .. check out our luxurious condo apartments. ???
Then there is this:
"Apartment buildings are converted to condos by means of a condominium declaration (called a "condo dec"), which also divvies up the percentage of ownership, defines which areas are commonly held by all owners, and states the building rules.
One of the most important things to remember about a condo, is that you don't actually own the unit you live in. You own the air inside the walls, ceiling and floor of the unit, and may also own the plumbing within your unit and perhaps a parking space. With your neighbors, you also jointly own the common elements of the property, which may include the roof, plumbing, lobby, laundry room, garden area or the garage."
... except that all condos I know of don't have a lobby or any common room. APARTMENTS DO!
So again I say.. WTF?