Early in any company search, most likely while obtaining a company profile, pay attention to whether or not the company is public or private.
A public company, or a publicly traded company is one where the company has sold stocks in stock trades such as the New York Stock Exchange. These companies are overseen by the U.S. Securities and Exchange Commission (SEC), and must file their financial information with the SEC, making it easy for anyone to assess the financial health of the company. Public companies, because they are able to sell stock, or shares in their company are able to raise funds for their own use.
A private company is one that is owned by an individual, family, or group of individuals that wish to keep a tight control over their company. Private companies do not need to share their financial information the way that public companies do, and it can sometimes be challenging to find out about the financial health of a private company. Be very aware that the financial data on a private company may be over a year old, and may be listed as an "estimate" only.