Labour (work) is the whole mankind activities, as it was understood for many centuries and in different regions of the world. Employment means paid work, that is human activities (labour) provided and exchanged through money. This economic concept was introduced especially by the Western cultures while stimulating an astonishing industrial development.

Nevertheless, attention is increased nowadays on the work opportunities determined by activities directly exchanged between persons without looking for money: social work, self-help, volunteer work, time banks that link people locally to share their time and skills, etc. This typology of work (labour) account for nearly 50% of production in developed countries (OECD) and 60-65% in developing countries, according to United Nations estimates.