What is Nudism/Naturism?

A pretty good start to get some education of naturism is the wikipedia page: https://en.wikipedia.org/wiki/Naturism (Fun Fact: if you give in "nudism" at wikipedia you land also at this page.) I like especially that the history of naturism is described. Also it is made clear that every country has its own naturism. I guess we can all learn about our naked culture movement which has ethical non-sexual values.