Why Trade Is Necessary

Everyone knows that a single person or community is unable to avail all the necessities of life itself, so people decided to fetch their necessary objects while communicating other people and communities. In this way they can get all the facilities of life. But how can they get other's things?
They would have to provide them something so that something could be get from them so they started making tools, clothes, pottery, shoes, furniture, jewellary and all other things which one need. In this way people were divide in different groups according to their occupation. They provided others with their necessities and others provided them theirs and vice versa. Today's whole modern import, export is based on the rule mentioned above.