Trade has always been important in human history, and today it plays a big role in globalization. The way countries trade with each other has changed over time, with new rules and agreements being made to make trade easier. One way to do this is through preferential trade agreements, which help countries trade more with each other. In South Asia, countries are trying to work together to reduce trade barriers and make it easier to trade with each other. This is important because South Asia has a lot of people, including many who are poor, but the region is not very well connected when it comes to trade. By studying how to get rid of trade barriers in South Asia, we can learn how to make trade better for everyone.