Ratio analysis involves calculating and analyzing relationships between financial data points to assess the financial position and performance of a company. It is useful for strategic decision making, financial planning, and identifying weak areas of a business. Key types of ratios include profitability, liquidity, activity, and leverage ratios. Profitability ratios measure profit earning capacity, liquidity ratios assess ability to meet short-term obligations, activity ratios evaluate efficient use of assets, and leverage ratios examine ability to meet long-term debt obligations. Ratio analysis is an important financial analysis technique.