[...] Labour is the specific or "real" act of working. Labour-power is the abstract "capacity to work": skills, knowledge, energy, etc. specific to each of those without access to means of productions except through capitalists. Wage workers do not sell "living labour," they sell the commodity labour-power on the labour market. The capitalist, who thus comes to control one more thing necessary for production (and the most important one at that--human energy and ingenuity) puts that labour-power to work as he or she sees fit, and pays the workers a wage for each unit of time they give up the control of their human energies.