Horizontal Analysis is a financial analysis technique that compares historical financial data over a series of periods. This method helps identify trends and growth patterns by examining line items in financial statements, such as the income statement or balance sheet, across multiple years. By calculating the percentage change from one period to the next, analysts can assess how specific items, like revenue or expenses, have evolved. This analysis is useful for stakeholders, including investors and management, to make informed decisions based on the company's financial performance over time.