A cryptocurrency exchange is an online platform that enables users to buy, sell, and trade digital currencies such as Bitcoin, Ethereum, and Monero. These exchanges act as intermediaries, matching buyers and sellers and often providing wallet services for storing digital assets. Users can typically exchange cryptocurrencies for other digital coins or for traditional fiat currencies like US dollars or euros. Security, fees, and available currencies can vary widely between exchanges, making it important for users to choose reputable platforms and take appropriate security precautions.