Employees are persons who, by agreement, work for a resident enterprise and receive a compensation for their labour. The relationship of employer to employee exists when there is an agreement, which may be formal or informal, between the employer and a person, normally entered into voluntarily by both parties, whereby the person works for the employer in return for remuneration in cash or in kind. The measurement is realized by the actual number of persons employed, and number of employees, both as head counts and, in the latter case, also in full-time equivalents (FTEs) defined as total hours worked divided by average annual hours worked in full-time jobs. The main uses of these characteristics are in stratification for sampling, analysis and dissemination purposes.