Systematic Risk:Systematic risk, also called market risk, is the risk inherent to the entire market or market segment. It is the risk that cannot be diversified away and affects all securities to some degree.
Diversification:Diversification is the process of allocating capital in a way that reduces the exposure to any one particular asset or risk. It is a risk management strategy that aims to mitigate unsystematic risk by investing in a variety of assets.
Portfolio Risk: Portfolio risk is the overall risk associated with an investment portfolio, which is a combination of systematic risk and unsystematic risk. Diversification can reduce the portfolio's overall risk by lowering the impact of unsystematic risk.