We are comparing the need of individuals to have jobs to fulfill their economic needs and the need that companies have of labourers to assure production.
For example, if the high tech sector is in full growth and that training programs for students are limited, the number of job offers will likely surpass the number of people available for these jobs. Hence, the offer will be higher than the demand, which is a very good situation for the job seeker. On the contrary, if the reverse is true and that job seekers surpass the job offers from companies, we risk being confronted by a very difficult "labour market".
In order to choose our career options carefully, we must consider our aptitudes, our abilities as well as future human resource needs.