Ratio analysis is a technique that involves regrouping financial statement data through mathematical calculations of relationships between items. It allows measurement of a company's overall performance regardless of size. Ratios are classified into liquidity, solvency, efficiency, and profitability ratios. Liquidity ratios measure short-term financial obligations, solvency ratios long-term financial position, efficiency ratios use of assets/liabilities, and profitability ratios ability to generate revenue. Key ratios discussed include current ratio, quick ratio, debt-equity ratio, gross profit ratio, return on capital employed, and earnings per share.