Beta is a term used in finance to measure the volatility of a stock or portfolio in relation to the overall market. It is a measure of systematic risk, which is the risk that cannot be diversified away by holding a diversified portfolio. A beta of 1 indicates that the stock or portfolio has the same volatility as the market, while a beta greater than 1 means it is more volatile and a beta less than 1 means it is less volatile. Beta is an important metric for investors to consider when making investment decisions, as it can help them understand the risk and potential returns of a particular investment.