The blockchain manages to solve several financial problems, currently when a person transfers money electronically, the bank is responsible for subtracting the money from your bank account and then adding the money to the receiver, thus avoiding the problem of duplicate bill.

With the blockchain, the bank is no longer needed to fall into the problem of duplicate money, when one transfers money, for example, one BTC, this transaction is copied on all computers that are connected to the blockchain, and each one transcribes instructions indicating that this bitcoin sent can only be used by the person who receives it.