Full employment
Full employment is the economic concept that refers to a situation where the entire active population of a country is working. This situation would imply that the markets are in perfect balance, companies would have no problem finding qualified personnel for their jobs and citizens would find employment at any time.
The concept of full employment is rather theoretical since it is hard to find a real case where unemployment is exactly zero. In practice, the labor market presents many imperfections: the workforce is always changing, people come and go to work for many reasons such as different interests, moving to another country, starting a new job or studies, etc. It is practically impossible to reach an exact moment in which the demand and supply of labor are equal, but it is an ideal situation and everything that means approaching it is positive.