Return On Equity - Definition

Return on common Equity (ROE, Return on average common equity) - Earnings before extraordinary items, less preferred-share dividends, divided by average common shareholders' equity. Shows the rate of return on the investment for the company's common shareholders, the only providers of capital who do not have a fixed return.

Return on total equity (ROE) - A measure of how well a company used reinvested earnings to generate additional earnings, equal to a fiscal year's after-tax income (after preferred stock dividends but before common stock dividends) divided by total equity, expressed as a percentage.

Source: http://gold.globeinvestor.com/public/help/flat/help_financials_report_ratios.html