The document defines and provides examples of four types of companies: 1) Growth companies reinvest most profits into expanding their business and experience significantly increasing cash flows and earnings. Google is provided as an example. 2) Defensive companies have stable sales and earnings during economic fluctuations. Utilities companies are given as examples. 3) Cyclical companies' revenues fluctuate with the business cycle, being higher in good economic times and lower in bad times. The airline industry is provided as a cyclical example. 4) Speculative companies invest significantly in uncertain projects that could fail or provide large returns if successful. Energy exploration companies are provided as engaging in speculative activities.