A cryptocurrency is a form of payment that can circulate without the need for a central monetary authority such as a government or bank. Instead, cryptocurrencies are created using cryptographic techniques that enable people to buy, sell or trade them securely. Cryptocurrencies can be exchanged for goods and services, though they often are used as investment vehicles. It is also a key part of the operation of some decentralized financial networks, where digital tokens are an important tool for carrying out transactions.