A digital coin is a digital asset. All digital coins use blockchain technology to save the history of transactions and to save the amount of coins present in an specific address.
There is no need for banks or any financial institute to make the transaction of digital coins possible, and they are transmitted through peer to peer networks that eliminates any middleman during the process
Bitcoin is the most famous example of digital coins.
Financial institutes have started using Bitcoin and it is gaining profound and ever increasing popularity.