Please explain the 7th line of second paragraph i.e. this led over a short..........deeply inequitable trade.

It means:

During the 16^th century few countries ruled over the entire world. Within short period of time, the economies of the colonized nations (nations which were annexed) were fulfilling the needs of the conquering powers (countries that ruled over other countries). This was done through inequitable trade practices. It was done by following certain practices. For example, the industries of the colonized nations were destroyed and agriculture was encouraged to provide colonizers with agricultural raw materials for their industries. Another way was that import duties were levied on the goods of the colonized nations while the conquering powers did not levy any duties on goods which they sold in their colonies.