Brought to you by Young Naturists America. We are a social acceptance organization that promotes naturism with a strong focus on advocating morals, ethics and social acceptance to the younger generation.
We would like to take this opportunity to explain the terms and lifestyle.
Nudism is the practice of being naked wherever it is allowed and accepted. The people who practice Nudism are referred to as "nudists". In nudism, the focus is on the nudity and being naked as much as possible. Some nudists also focus on getting others to live a clothes free lifestyle as well.
Naturism is the practice of living a clothing optional lifestyle wherever society deems it acceptable. Naturism is practiced by people who are referred to as "naturists". In naturism, the focus is on acceptance of others where nudity is enforced as way of promoting body acceptance and healthy living.
A nudist is a person who practices nudism. A nudist will seek out locations for being nude just for the sake of being nude. There is no true moral or ethical component to this lifestyle.
A naturist is someone who practices naturism. A naturist will mostly seek out locations that are natural with a focus on public lands and or beaches. A naturist lifestyle has core ethics and values that one needs to adhere to in order for them to truly be called a naturist.
In America, the two terms are used interchangeably but that is a mistake. The main organization for nudism in the USA promotes "nude recreation". Nude recreation by definition, is more of a hobby or activity where people can and will be naked. While naturism (which is also the preferred term in European countries) is more of a lifestyle choice, and the ethical roots go far deeper than purely being nude in public.
In either case, the individuals will seek out activities where they can enjoy social nudity.
For the record, we would like to make note of the fact that naturalism and by default - naturalists - are basically biologists (think Charles Darwin). Many nudists and naturists will correct you if they are referred to as naturalists.
For more information about Nudism and Naturism, please refer to these websites:
Wikipedia has quite a large resource of information.