The Markowitz Model, developed by economist Harry Markowitz in the 1950s, is a framework for constructing an optimal investment portfolio. It emphasizes the importance of diversification, suggesting that investors can reduce risk by combining different assets that have low correlations with each other. This approach helps in achieving the best possible return for a given level of risk. The model introduces the concept of the efficient frontier, which represents the set of optimal portfolios that offer the highest expected return for a defined level of risk. By analyzing the risk-return trade-off, the Markowitz Model assists investors in making informed decisions about asset allocation.