Mercantilism is an economic practice by which governments used their economies to increase state power at the expense of other countries. European mother country extracted raw materials from the colonies. They sold finished goods back to the colonies. The sole purpose of the colony was to make the mother country rich and self sufficient. Governments sought to ensure that exports exceeded imports and to accumulate wealth in the form of bullion, mostly gold and silver.  This is called a favorable balance of trade.  In mercantilism, wealth is viewed as finite (Limited Amount) and trade as a zero-sum game. Mercantilism was the prevalent economic system in the Western world from the 16th to the 18th century.

Edited from: https://www.britannica.com/topic/mercantilism