Crypto exchange or digital currency exchange (DCE) is a business that allows customers to trade cryptocurrencies or digital currencies for other assets, such as conventional fiat money, or different digital currencies. They can be market makers that typically take the bid-ask spreads as transaction commissions for their services or simply charge fees as a matching platform. DCEs may be brick-and-mortar businesses, exchanging traditional payment methods and digital currencies, or strictly online businesses, exchanging electronically transferred money and digital currencies.