A condominium is always a form of real estate ownership, regardless of the style of the home.
A townhouse is a style of home and can be owned outright, rented or owned as a condominium.In some...
The correct use is actually "different from". However, you will find "different than" commonly being spoken across the US. This does not mean it is correct.
Different from is correct. Consider saying 'This marble differs FROM this marble' and apply it to different. 'Different than' is an Americanism. However, it's preferable to the heinous 'different...