A unit of cryptocurrency is a TOKEN, which is a digital asset that can be used as a medium of exchange. Tokens are created and stored on a blockchain, which is a distributed ledger technology that records and stores transactions. Tokens are typically used to purchase goods and services, or to represent ownership of an asset. They can also be used to pay for fees associated with transactions on the blockchain. Tokens are often used as a form of payment in Initial Coin Offerings (ICOs), which are crowdfunding campaigns that use cryptocurrency to raise funds.