Digital currency is a type of currency that has no physical form and only exists in digital form. Digital currencies include virtual money and cryptocurrency. This digital money may be used as traditional money to buy and sell goods, but with the allowance of instant transactions and borderless transfer-of-ownership. Digital money can be restricted to a certain community or be fully free for anyone to use. Digital money can also be decentralized or have a central authority over an emission process, can be backed by other currency or liquid asset, or work without any backing. Investing in digital currency has become very popular after the explosion of cryptocurrencies due to their volatility, which makes them a great speculation tool. Although digital currencies are useful and progressive, they are not yet widespread and most banks do not accept them.