If you're new to investing in stocks, then Earnings per Share is perhaps the single most important topic you should understand before investing money in the market. Because of the importance of earnings to shareholders, a great deal of time is spent developing and evaluating earnings per share estimates.

There are three types of Earnings per Share (EPS) numbers:

• Trailing EPS – last year’s numbers and the only actual EPS
• Current EPS – this year’s numbers, which are still projections
• Forward EPS – future numbers, which are obviously projections

Companies understand how important Earnings per Share are to the market and shareholders and they often publish what are called earnings calendars - which is the date that a company will report out their most recent earnings. They might also conduct what is called an earnings conference call to discuss possible changes in their financial outlook that might affect future earnings.