Anything that is easily used as a medium of exchange in settling a trade is called money. Earlier demanded commodities like salt, rice wheat, weapons, livestock was used as money, it was called barter exchange. After that metallic money like gold, silver, copper come into existence. They were quiet popular. Soon this money was found inconvenient as well as dangerous to carry, so replaced by paper currency. Every country prints its own fiat currency as per their policy; generally these currencies are printed and controlled by the central bank of that country. After economic revolution paper money is accompanies by credit money, plastic money etc. The latest form of Digital money (bitcoin) gets introduced in the year 2009. Purpose of all forms of money is to make the trade simple and easy.
Yeah thats right the new evolution of money is the digital currency it less hussle and you dont have to afraid to carry this money. and a simple click you can also buy for goods and even pay your utility bills. Digital money is really make our currencies more flexibility and hussle free. But i think the evolution of money is not end on digital money maybe this evolution is start on his journey for more opportunity for our world iknow someday it change the world the way how we use money from basic goods to metalic to paper money and to digital currencies.