Unemployment refers to willing workers who are physically and mentally able to work but cannot find jobs. It occurs when there is an imbalance between the number of available jobs and job seekers. There are several types of unemployment, including frictional, seasonal, cyclical, structural, and voluntary unemployment. High unemployment can negatively impact individuals through loss of income and self-esteem, and negatively impact the economy through lower tax revenues and GDP. Governments aim to reduce unemployment through demand-side policies like government spending and supply-side policies like job training programs.