The Dividend chart for O'reilly Automotive (ORLY) shows us the per share payout over time.

Dividends are a distribution to shareholders, and they define how much money a company is providing to its shareholders after all taxes and expenses have been paid. Before a company can pay shareholders a dividend, the company must pay taxes on the earnings, and then the shareholders must pay taxes too.

Dividend income is therefore exposed to double taxation. Dividend income may be treated differently by various types of shareholders, and tax liabilities may change accordingly, but the company issuing a dividend will have had to either pay taxes on the earnings that generated the money to pay the dividend or would have had to acquire the cash in some non-taxable event.

Normally, if a company pays a dividend to its shareholders, part of the EPS is shared with the shareholders, part of the EPS is deposited as cash reserves, and the rest is designated elsewhere.

The cash reserves are important because if a company cannot pay a dividend because of an adverse temporary operating environment the company would draw from those reserves, pay the dividend from cash on hand, and keep its shareholders happy until normal operating conditions resume.

Often, shareholders rely on dividends as a source of income, so a steady, reliable, and consistently growing dividend is often considered favorable by the investment community.

Here is how the Dividend Yield is calculated:

Dividend Yield = (dividend per share)/(price per share).