The main difference between an apartment and a condominium is ownership. The term apartment is usually applied to a unit in a building that is rented. Whereas condominiums contain individually owned units. There are many other small differences between an apartments and condos, (condominiums offer services and facilities such as gyms, swimming pools, and club houses) but ownership is the most distinctive.

It's a difference in the legal structure and ownership. A building may start out as an apartment building, in which people pay monthly rent and do not legally own their units. If local laws permit and the owner takes the right legal measures, the owner can convert the building to a condominium complex, and begin selling the units instead of renting them. The exact same unit in the exact same building could be an "apartment" one year and a "condo" the next.