Unlike traditional central bank account-based currencies such as reserves, or decentralized cryptocurrencies like bitcoin, China’s digital currency would be controlled by the country’s central bank and will be instantly made available at a moment's notice to anyone who can receive it.
The digital yuan is also trackable, adding another tool to China’s heavy state surveillance. The government deploys hundreds of millions of facial-recognition cameras to monitor its population, sometimes using them to levy fines for activities such as jaywalking. A digital currency would make it possible to both mete out and collect fines as soon as an infraction was detected.
Further, and in a fit of complete insanity, the Chinese will make the digital yuan programmable. They are testing the idea of making the currency have an expiration date. If you don't spend it by, say, Thursday next week, it becomes worthless. The idea is to encourage the velocity of money for times when the government thinks the economy needs a jump start.
If the Red Chinese think anyone will be attracted to a currency that they completely control and can make valueless at their whim, they are gravely mistaken.