Today, we are living in the age of communication, using the telephone, television, films, and the Internet. Even books, magazines and newspapers are important means of communication. Various means of transport and communication have reduced distances, bringing the world closer. Modern life is so complex that one has to depend on others. The same is true of the countries as well. No country today can prosper without the co-operation and assistance of others. This requires the movement of goods and materials between countries. Trade provides us with our necessities and also adds to the amenities and comfort of our life. We may also notice that they are rightly called the lifelines of our national economy.