Definition of 'Full Employment'
A situation in which all available labor resources are being used in the most economically efficient way. Full employment embodies the highest amount of skilled and unskilled labor that could be employed within an economy at any given time. The remaining unemployment is frictional.
Investopedia explains 'Full Employment'
Frictional unemployment is the amount of unemployment that results from workers who are in between jobs, but are still in the labor force. Full employment is attainable within any economy, but may result in an inflationary period. The inflation would result from workers, as a whole, having more disposable income, which would drive prices upward.
Many economists have estimated the amount of frictional unemployment, with the number ranging from 2-7% of the labor force.