- Dr. S. Vijay Kumar Every branch of knowledge has its fundamental discovery, in mechanics it is wheel, in science it is fire, in politics it is vote. Similarly, in economics it is the money which is the essential invention on which all rest is based. Money as a means of payment consists of coins, paper money and withdrawable bank deposits. In India, t he rupee and the half rupee coin are unlimited legal tender, while all other coins are limited legal tender up to Rs.10. Today, credit cards and electronic cash form an important component of the payment system. For a common person th...