Digital currencies are forms of money that exist only in electronic form. They can be used for online transactions, allowing people to buy goods and services over the internet. Unlike traditional currencies, such as the US Dollar or Euro, digital currencies are not issued by a central authority like a government or bank. One popular type of digital currency is Bitcoin, which was created in 2009. Digital currencies can be stored in digital wallets and can be transferred between users through secure networks. They often use technology called blockchain to ensure transparency and security in transactions.