Labour economics seeks to understand the functioning and dynamics of the markets for wage labour. Labour is a commodity that is supplied by labourers in exchange for a wage paid by demanding firms.
Labour markets or job markets function through the interaction of workers and employers. Labour economics looks at the suppliers of labour services (workers) and the demanders of labour services (employers), and attempts to understand the resulting pattern of wages, employment, and income. Labour markets are normally geographically bounded, but the rise of the internet has brought about a 'planetary labour market' in some sectors.
Labour is a measure of the work done by human beings. It is conventionally contrasted with such other factors of production as land and capital. Some theories focus on human capital (referring to the skills that workers possess, not necessarily their actual work). Labour is unique to study because it is a special type of good that cannot be separated from the owner (i.e. the work cannot be separated from the person who does it). A labour market is also different from other markets in that workers are the suppliers and firms are the demanders.