Unemployment refers to a situation where a person actively searches for employment but is unable to find work. Unemployment is considered to be a key measure of economic health. The most frequently used measure of unemployment is the unemployment rate. It's calculated by dividing the number of unemployed people by the number of people in the labor force.

Unemployment is a key economic indicator because it signals the ability to obtain gainful work and contribute to the productive output of the economy. More unemployed workers means less total economic production.

There are many reasons for unemployment. These include recessions, depressions, technological improvements, job outsourcing, and voluntarily leaving one job to find another.​

The unemployment definition doesn't include people who leave the workforce for reasons such as retirement, higher education, and disability.