by Rentchamber 
The differences between a Flat, Apartment, or Condo can be a bit confusing as a result of several factors-particularly geographical locations. Ghana being a former British colony tends to refer to a lot of stuff the same way the British do. But with the advent of rapid globalization comes the influence of American English on Ghana’s socio-politico-economic dispensations.
Flat: This term is very British and therefore not in much use in the U.S. Basically it is the same as “an apartment”. Just a different way to say it.
Apartment: Americans tend to call a “unit” in a building an apartment if the person who owns the entire building rents out ALL of the units. They call it a “condo”, even if the condo owner rents it out or if all of the units in the building are individually bought and sold.
Townhouse: We, the real estate industry, kind of made that word up and in and of itself doesn’t have a particular meaning. Often it distinguishes between stacked, one-floor dwelling units in a building and attached more than one-floor dwellings. Both can be “condominium” ownership or not. The main difference is you have more than one level. While typically townhomes, whether condos or fee simple ownership, are attached dwellings. Many are not attached to dwellings. I will explain that better in the “condo” answer to your question.
“Condo”: as noted above is a one-floor unit in a building where the units can be bought and sold individually as separate legal entities. However, the slang term “condo” is like the slang term “townhouse”. Not “legal” definitions, however, “condominium” is different, and “condominium” and “condo” are not the same
While you didn’t ask about “Condominium”, it is key to understanding everything above. In Residential housing, everything breaks down into two legal forms of ownership. Fee Simple Ownership and Condominium Ownership. Most of the rest is just “jargon”. Most Single Family homes are “fee simple” ownership. Most “condos” are condominium ownership. So let’s look at “townhome” and why some are Fee Simple ownership and others that are identical are Condominium Ownership.
Let’s say you build 8 townhouses attached to one another in a row. These can be just another name for “rowhouses” or they can be “condo townhomes” depending on whether or not you subdivide the lot into 8 pieces or not. Standing outside looking at them, they will be identical. You will only be able to tell by knowing the lot differences by checking the legal lots.
Example below:
So while you say ‘condo” and “townhouse” as if they are two different things, and most people do refer to them that way, a townhouse is sometimes “a 2-story condo” and sometimes a townhouse is a single-family home. The only difference is whether or not you buy the land under it as a separate lot or you buy the land under it as a 1/8th interest owner in the larger piece, making it a condominium.
Townhouses and Townhomes are just a “style” like a colonial or a mid-century modern. It’s important to know when you are buying a “townhome” if you are buying the land with it separately, or you are buying it as a “condo-townhome” since you can not tell the difference by looking at them physically from the inside or from the outside.
Credit: Quora: Ardell DellaLoggia, Real Estate Broker Seattle-Kirkland WA.
