What do currency mean or do?

Currency is a system of money that serves as a medium of exchange for goods and services within an economy. It facilitates trade by providing a standard measure of value, enabling transactions to occur more efficiently than barter systems. Additionally, currency can serve as a store of value and a unit of account, allowing individuals and businesses to save and plan for future expenses. Different forms of currency can include physical notes and coins, as well as digital currencies like cryptocurrencies.