An apartment is a self-contained housing unit that occupies only part of a building.  Such a building may be called an apartment building, apartment house, block of flats, or high-rise, especially if it consists of many apartments for rent. Apartments may be owned by multiple owners and therefore rental rates and amenities may vary by unit.

Leasing an apartment has several distinct advantages over renting or buying property. Because landlords can depend on many months of income, a lease often costs less than a rental over the same period of time. Tenants who lease may forgo some of the responsibilities of homeowners, including paying property tax, performing basic maintenance and ensuring that the property meets building and fire codes. Finally, leasing an apartment doesn't require a large down payment, which allows tenants to live in cities or regions where they may be unable to afford homes.