The first role of money is to be a store of value- something that is expected to retain its value in a reasonably predictable way over time. Gold or silver that was mined hundreds of years ago would still be valuable today” (source)  – So think of it as something that doesn’t really get affected by inflation, and hence won’t lose its value. Money’s second role is to be a unit of account. The thing that goods and services are priced in terms of. For example, the price of items you see on menus and tags. Pound is currency of the United Kingdom, but it could be a type of good instead. It could also be barter: ‘give me 5 goats if you want my new horse.