What is Capital Market Line?

Legal Definition
Capital market line (CML) is the tangent line drawn from the point of the risk-free asset to the feasible region for risky assets. The tangency point M represents the market portfolio, so named since all rational investors (minimum variance criterion) should hold their risky assets in the same proportions as their weights in the market portfolio.
-- Wikipedia
Legal Definition
A relationship within the CAPITAL ASSET PRICING MODEL (CAPM) that relates the expected return of a PORTFOLIO to its expected RISK (as measured through STANDARD DEVIATION). Under CAPM, all investors will choose a position on the capital market line by borrowing or lending at the RISKFREE RATE, since this maximizes return for a given level of risk. See also SECURITY MARKET LINE.