Org domain names, as all original top level domain names, were created in January 1985. In the first place .org was intended to be used by organizations, whom did not meet the requirements of the other generic top level domains.

These days anyone can register a .org domain. Org domains were also intended to be used by individuals, but there are also alternatives, like .name and .info.

There are countries in the world that have a second-level domain with a similar purpose. They have the following form .org.xx. Xx being the country code top level domain.

Org domain names are most likely to be used by non-profit organisations. If you need to register a .org domain, be sure to use relevant keywords in your domain name. This makes it much easier to be noticed. You can research keywords for example, via Google's Adwords program, or via software like WebCEO.

It is clear that an oganisation, like an individual both will benefit from keyword research, before choosing the exact domain name. To be noticed you need to use these keywords which describe you or your organisation at best, and that people are looking for by search engines.

Look for keywords that are popular = a lot of people are looking for, yet look for keywords with little competition = are used by fewer websites as keywords. Google's keyword tool, on the Adwords site can help you out with that one.