The Weighted Average Cost of Capital, or WACC, provides a comprehensive view of a company's cost structure by incorporating the costs associated with both debt and equity financing. This measure is significant as it accounts for the weighted risk associated with each source of capital. Equity is typically riskier than debt, reflected in a higher cost because, in the event of liquidation, equity investors are paid after debt holders.

In business, WACC is crucial for several reasons:

1. Investment Decisions: It helps companies decide which projects or acquisitions align with shareholder interests based on expected returns.
2. Performance Assessment: Companies use WACC to assess their financial health and operational efficiency. By comparing the actual returns on investments to the WACC, management can determine whether they are generating sufficient returns relative to the risks and costs of their capital.
3. Optimizing Capital Structure: Understanding WACC enables companies to tweak their mix of debt and equity to minimize their cost of capital. By strategically managing this balance, companies can enhance their value and improve their creditworthiness.

As a result, WACC reflects the cost of capital and serves as a strategic tool in financial planning and corporate governance.