Blockchain can be categorized as a decentralized ledger across a peer-to-peer network. Making use of the network, participants can confirm transaction without the need for a central certifying authority.
The use of blockchain is not just limited to bitcoins or the broader category of cryptocurrencies, in fact, the potential implementation of blockchain technology includes fund transfers, settling trades, healthcare, telecoms, voting and many other areas.
In future, it is expected that the simplified transactions facilitated by blockchain will become the basis for smart contracts.
To know more about blockchain and why retail banking executives should care about it, read here.