Narrow specialization of tasks within a production process so that each worker can become a specialist in doing one thing, especially on an assembly line. In traditional industries (see sunset industries), division of labor is a major motive force for economic-growth. However, in the era of mass customization (which requires multiple skills and very short machine change-over time), division of labor has become much more flexible. Also called specialization of labor.
Khanacademy.org overview hope this helps :)
