Why do they need a blockchain ? Can't run a database anymore ? Should I be worried about my bank savings ? I still have to meet that one person that can explain to me what a bank does with a blockchain.
They can use blockchains to store unalterable records in. Any bank could check a record and know it was legit without needing to trust any other bank. Banks do business between themselves, and they often have to move massive amounts of money to a bank on the other side of the world. Keeping records of that in a blockchain would be safer than in a database because a database can be altered. but a blockchain cannot.