ROI, or Return on Investment, is a key metric used to evaluate the financial effectiveness of an investment, including cybersecurity initiatives. In cybersecurity, ROI measures the value gained from investments in security tools, services, or processes compared to their costs. Calculating ROI helps organizations justify cybersecurity spending by demonstrating how investments reduce risks, prevent losses, or improve operational efficiency. A positive ROI indicates that the benefits, such as avoided breaches or compliance fines, outweigh the investment costs. Understanding ROI enables decision-makers to allocate resources wisely and prioritize security projects that deliver the greatest financial and strategic value.