How you can say that transport, communication and trade are complementary to each other?

For a long time, trade and transport were restricted to a limited space. With the development in science and technology, the area of influence of trade and transport expanded far and wide. Today, the world has been converted into a large village with the help of efficient and fast moving transport. Transport has been able to achieve this with the help of equally developed communication system. Therefore, transport, communication and trade are complementary to each other.