The difference between a condominium and an apartment is purely legal: there is no way to know a condo from an apartment simply by looking at or visiting the building. What defines a condominium is the form of ownership. The same building developed as a condominium (and sold as individual units to different owners) could actually be built someplace else as an apartment building (the developers would retain ownership and rent individual units to different tenants).

Typically, a condominium consists of multi-unit dwellings (i.e., an apartment or a development) where each unit is individually owned and the common areas, such as hallways and recreational facilities, are jointly owned (usually as "tenants in common") by all the unit owners in the building. It is also possible for condominiums to consist of single family dwellings: so-called "detached condominiums" where homeowners do not maintain the exteriors of the dwellings, yards, etc. or "site condominiums" where the owner has more control and possible ownership (as in a "whole lot" or "lot line" condominium) over the exterior appearance. These structures are preferred by some planned neighborhoods and gated communities.

In India Condominiums are more commonly known as "flats" in India. This type of housing is very common in larger cities but are not commonly found in rural areas. In India, they are registered as "co-operative housing society" rather than condominiums in that the owners actually have a share of the co-op and not the actual real estate itself. Owners can sell the "share" in the open market, but they must receive approval from the co-op to complete the transaction.