Economics as a subject has evolved through the ages. Primarily, it only dealt with the financial matters of an empire. As production of different things were invented, different sectors and markets developed, subject matters of economics broadened. Analysis of production relations, labor relations and market relations became the subject matters of Economics. With the creation of nations, the development activities of the nation as a welfare state got included in Economics. Economics started to deal with development theories, growth theories and money markets. In modern times, the money and capital markets are so matured that intense knowledge of economics can only analyze the happenings. To know about world trade, trading between different countries and the economic relations between the nations, one has to study Economics of Trade and Business, which is also popularly known as International Trade. Since sixties, study of economics is not only confined within economic affairs, it started to explore humanitarian aspects of the economic relations. Therefore, Welfare Economics and Environmental Economics flourished to deal with the welfare of the societies and nations, and the environmental issues. Thus today, Economics has become a vast area of study. Study of economics in modern times is basically based on Mathematics and Statistics. As it is a very broad subject, it has many vast branches. Theoretically, economics has many branches like Micro Economics, Macro Economics, Economics of a nation, study of Capital Markets, International Trade, Development Economics, Public Finance, and Environmental Economics. Econometrics, Mathematical Economics are the branches of Economics , which are used as tools to study the subject and analyze the economic relations. While studying this subject, data of different sectors are studied and analyzed vividly for understanding economic conditions of the nations, markets, different sectors of an economy and business cycles. Therefore, knowledge of statistics is also required to learn Economics.