Question

why does money transaction is necessary better than barter system

Answer 1

money can be used as medium of exchange. in barter system goods are exchanged against goods so every item does not have individual value and needs souble coincidence of wants. example a milk producer needs rice so he needs to find a rice farmer who wants to sell his rice and take milk. but as money as exhange medium now the milk producer can sell the milk for money and buy the rice from the market.