Specialization is the separation of tasks within a system. In a multicellular creature, cells are specialized for functions such as bone construction or oxygen transport. In capitalist

Capitalism

Capitalism is an economic system that became dominant in the Western world following the demise of feudalism. There is no consensus on the precise definition nor on how the term should be used as a historical category...

 societies, individual workers specialize for functions such as building construction or gasoline transport. In both cases, specialization enables the accomplishment of otherwise unattainable goals. It also reduces the ability of individuals to survive outside of the system containing all of the specialized components.

Adam Smith

Adam Smith

Adam Smith was a Scottish social philosopher and a pioneer of political economy. One of the key figures of the Scottish Enlightenment, Smith is the author of The Theory of Moral Sentiments and An Inquiry into the Nature and Causes of the Wealth of Nations...

 described economic specialization in his classic work, The Wealth of Nations

The Wealth of Nations

An Inquiry into the Nature and Causes of the Wealth of Nations, generally referred to by its shortened title The Wealth of Nations, is the magnum opus of the Scottish economist and moral philosopher Adam Smith...

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Specialization is when people specialize in one thing or another which they are good at.