Public – A company is considered public if its shares of equity is traded on a stock exchange. Public companies are required to submit filings to the SEC, making information much easier to locate.
Publicly traded companies have ticker symbols, which act as a unique identifier on the exchange they are traded on. You can search databases using a company's ticker symbol narrowing your results to exactly the company you are looking for. To find financial information and SEC filings for public companies look for a link to "Investor Relations."
Subsidiary – A company that operates under the control of a larger parent company is a subsidiary. The parent company may be a private or public company. The parent company may not disclose financial performance of individual subsidiaries. You may need to read the management discussion in SEC filings such as 10-K, study the information provided on the subsidiary’s and parent company’s websites, or find news articles in order to find information about financial performance and strategy.
Look up Ticker Symbol: Yahoo! Finance
Private – A company is considered private if it is not traded on a stock exchange and is not owned by a larger parent company. They are not required to submit SEC filings, which can make finding financial information a bit trickier, if it is available.
Don't forget to look for information on the company's website. You can often find information that can be useful including news releases, SEC filings and annual reports (for public companies), corporate governance, and strategy by studying the website.