Public companies have stocks that are bought and sold by the public on one of the stock exchanges. The Securities and Exchange Commission (SEC) requires publicly traded companies to file extensive information with them, which is all available online.
Begin your search by identifying the public company's "ticker symbol," since this can be used as a quick look-up key in other sources. Scott Trade provides a ticker symbol search, as does Google Finance. If you can't find a company at one of these sites, then it is likely privately held.
Examples of area public companies:
Privately held companies do not have stock available for public purchase. Since private companies are not required to disclose information to the SEC, freely available information on them is more difficult to find.
Examples: Cascade Engineering in Grand Rapids; Haworth, Inc.; and Shell Oil
Like their name suggests, nonprofit organizations do not distribute their revenue, do not have stock, and are controlled by boards. Information on nonprofit organizations is sometimes difficult to find, but they do usually distribute some information in their annual reports and online.
Examples: United Way and the Girl Scouts of America