Basements and cellars often differ in terms of size, decoration, relation to the ground level, presence of windows and level of protection from bad weather. They also differ in terms of function, as people usually use cellars mainly to store things, whereas they use basements for a variety of functions.
Basements often have much more space than cellars, and finished basements may even have multiple rooms, such as bedrooms and bathrooms. This larger space also means that basements are more difficult to heat than cellars. Even unfinished basements have potential space for several rooms, such as game rooms or large bars, whereas many cellars are too small. Some people also rent out spare rooms in their basements. Some basements have drywall and decorations, whereas many cellars do not.
Many basements have windows on one side and also may have doors going outside. Cellars rarely have windows and do not normally have glass doors to the outside. Although both basements and cellars offer a level of protection against tornadoes and other bad weather, cellars are often safer because they are further in the ground. Basements are often only halfway under the house, and less than halfway under the curb, whereas cellars often go most of the way below the curb.