Employment comprises all persons of working age who during a specified brief period, such as one week or one day, were in the following categories: a) paid employment (whether at work or with a job but not at work); or b) self-employment (whether at work or with an enterprise but not at work).
The working-age population is the population above the legal working age, but for statistical purposes it comprises all persons above a specified minimum age threshold for which an inquiry on economic activity is made. To promote international comparability, the working-age population is often defined as all persons aged 15 and older, but this may vary from country to country based on national laws and practices (some countries also use an upper age limit).
Information on occupation provides a description of the set of tasks and duties which are carried out by, or can be assigned to, one person. Employed persons are classified by occupations through their relationship to a present job.
Data presented by occupation is based on the International Standard Classification of Occupation (ISCO). The development of the ISCO goes back many decades and has always been closely connected with the work of the International Conference of Labour Statisticians. The original version of the ISCO was published in 1958 (ISCO-58) and it has been revised three times since then: in 1968 (ISCO-68), in 1988 (ISCO-88) and in 2008 (ISCO-08).
Statistics on employment by occupation are presented in ILOSTAT according to both the categories of the latest version of the ISCO available and broad skill levels, based on the following correspondence table: