Nudity, or nakedness, is the state of wearing no clothing. The wearing of clothing is a predominantly human characteristic arising from functional needs such as protection from the elements and from cold temperatures, after the loss of body hair, and migration to colder regions. The amount of clothing worn depends on functional considerations, such as a need for warmth, as well as social circumstances. In some situations, a minimum amount of clothing or none at all may be considered socially acceptable, while in others much more clothing may be expected. Social considerations involve issues of modesty, decency and social norms, besides other considerations, and these may depend on the context. There may also be legal considerations.
Full nudity refers to complete nudity, while partial nudity refers to less than full nudity, with parts of the body covered in some manner. The term partial nudity is sometimes used to refer to exposure of skin beyond what the person using the expression considers to be within the limits of modesty. If the exposure is within the standards of modesty of a given culture and setting (e.g. wearing a bikini at a non-nude beach), terms such as nudity, partial or otherwise, are not normally used. If however, the degree of exposure exceeds the cultural norms of the setting, or if the activity or setting includes nudity as an understood part of its function, such as a nude beach, terminology relating to nudity and degrees thereof are typically used. Toplessness is regarded by most people as partial nudity.
Full frontal nudity describes a state of full nudity with the subject facing forward with the whole front of the body exposed, including intimate parts such as a man's penis or woman's vulva. Partial frontal nudity typically only refers to the exposure of the breasts. Non-frontal nudity describes nudity where the whole back side of the body, including the , is exposed, or a side-view from any other direction.