What is block chain? How is the future on Block chain?

Ok, Everyone knows the official definition of Block chain, but what exactly it is ? Just like Bank maintains all the transactions in the data base. Block chain enters and maintains all the Bitcoin transactions in server. It's a nutshell explanation! Hope you get the idea -As a distributed ledger, blockchain reduces the costs involved in verifying transactions, and by removing the need for trusted "third-parties" such as banks to complete transactions, the technology also lowers the cost of networking, therefore allowing several applications.[ The primary use of blockchains today is for the creation of cryptocurrencies, such as bitcoin. The future depends on Government policies and How the Regulation takes place. It is still in an Early stage. read less