Money is the general word for the notes and coins used to buy things. Currency is used to refer to the money of a particular country. Cash is used to emphasize the reference to notes and coins (and not credit cards or cheques). Change refers to coins, or to the money you get back when you pay for something. money Can you lend me some money? How much money do you need?
currency The local currency is the euro. This bank can supply you with foreign currency. cash You have to pay in cash, they don't accept credit cards. All the cash was taken by the burglars.
change Excuse me, have you got change for a dollar? Here's your change, madam.