A Central Bank Digital Currency (CBDC) is a digital form of legal tender issued directly by a nation's central bank, carrying the same legal status as traditional banknotes but circulating in digital form on a chain or closed system. CBDCs are essentially 'government-issued stablecoins': they need no private entity backing because they are the legal currency itself. The fundamental difference from private stablecoins like USDC: CBDCs are directly controlled by government, carry the highest credit backing, but consequently bring stronger surveillance capability and programmable spending restrictions. The most scaled CBDC to date is China's digital yuan (e-CNY); over 50 countries and regions are actively researching or piloting CBDCs.