The domain of a website indicates the type of entity responsible for creating and maintaining the site. The domain can be found in the site's URL and is always preceded by a "." Below is a list of some domain names with more information.
.edu - Maintained by educational institutions ranging from elementary through college. These are generally reliable sources, particularly if they are maintained by a college or university department or research center. However, be weary of personal student websites which may be hosted under a .edu domain but are not necessarily reviewed by the institution.
.gov - Maintained by various areas of the federal government and can generally be trusted. These are particularly useful for statistical inforamtion such as census or employment data as well as legal information such as Congressional hearings and Supreme Court rulings.
.il.us - Maintained by various branches of the Illinois state government. This would also apply to any of the other 50 states such as wi.us, in.us, mi.us, etc. State sources are generally reliable and are particularly useful for state governement information such as state tax or health department information as well as websites hosted by individual towns or municipalities.
.net - This is a generic domain name that could was originally intended for network technology groups but has come to encompass commercial and individual interests as well. These sources should always be closely evaluated.
.org - Most commonly maintained by non-profit organizations which are usually credible, unbiased sources. However, be weary of non-profit organizations that strongly advocate specific points of view such as many lobby or activist organziations. While these organizations may provide credible information, be sure to check that this information is supported by cited sources and that you have evaluated all sides of this issue in other sources. Be sure to consider whether this organization is supported by commercial interests which may introduce bias.
Common English-speaking country domains: .au=Australia; .ca=Canada; .uk=United Kingdom