The functions of money 

Money is used as a means of exchange – that is, it can be exchanged for goods or services. It is a store of value – it does not have to be spent immediately - it keeps its value (or at least most of it) until you are ready to spend it. Money is counted as legal tender so it can be used to pay taxes and in contractual arrangements and it is also a unit of account– it gives market value to goods and services.