What is the difference between currency and coin?

Currency is a form of money. The British Pound, US Dollar, Australian Dollar, Canadian Dollar, Euro, etc are all different types of currency.

Coins ,usually made of metal, is money a government produces as part of their currency. Pennies, nickels, dimes, quarters, 10 pence, 20 pence, 50 pence, 10 cents, 50 cents, etc. are all different types of coins.