The labor force is the number of currently employed people as well as those who are not yet employed but are actively looking for work. The labor force does not include retirees or students, nor does it include people who would like to have a job in the future but are not currently looking for one, or are in a passive search for one.
Most of the research done on work and employment issues is precisely about the labor force, and builds its samples on the responses of employed professionals and active candidates. Trends about work and employment are also aimed at this segment of society. The stratification of the workforce by, for example, baby boomers, millennials, generation z, etc., is worth considering.