The belief and practice that it is a natural and pleasant experience to not wear clothing. For example, nudists treasure being naked outdoors, something that is illegal in most places.
Nudism does not imply always being naked; clothes are useful things. Among other things, they protect against inhospitable weather and protection from abrasion.
Nudists believe that it's perfectly acceptable to be seen naked as well as to see others naked, and that this need not be a sexual experience. Rather, they maintain that the association of sexual arousal with nudity has more to do with culture than with human nature.
Since practicing nudists frequently see one another naked without becoming aroused, they have considerable evidence to support this view.
Nudism is also sometimes called naturalism.
For more information on nudism, you go to the website given below. However, be warned that this website contains non-pornographic nudity.
http://apollon.cha.forthnet.gr/happynature/index.html