Money is one of the important concepts, This section talks about money from the perspective of microeconomics.when people exchange goods and services without using money, this is called barter. "I'll cook dinner if you'll do the dishes" is an example of barter. Imagine an economy in wich i can sell services as a consultant to banks, but what i want is to buy a new suit. the clothing store that sell suits does not have any use for my services as a banking consultant. i sell consulting services for money, and i buy a suit using money. money serves as a medium of exchange. the bank does not sell suits. how can barter work?
Barter system is not in practice anymore that is why we have fiat system, initially gold act as medium of exchange but its physical structure said to be heavy so people print money backed up by gold but later everything under their control.