Blockchain is the biggest revolution that we are witnessing in the space of financial transaction, this would change how we transact and do business with physical goods in future.
Today when we do a cashless transaction, one of the two parties has to pay a third party for making that cashless transaction possible. With Blockchain the third party will be eliminated, transaction between two people will be as simple as exchanging something without any intervention of third party like bank. Blockchain acts as a ledger in which all the transactions are recorded in packages called blocks. These blocks are written every 10 minutes and stored in proper linear, chronological order with every block containing a hash of the previous block. Each block contains data, which is cryptographically hashed. The blocks of hashed data draw upon the previous one and ensure all data in the Blockchain has not been tampered and remains unchanged. You can save anything securely on Blockchain.
In Blockchain, there is no centralized authority that is responsible for saying what is true or what is false, rather multiple distributed parties come to consensus, that consensus is entered into the ledger which thereafter can be accessed by anyone in the future. It is computationally infeasible for a single person (or anything less that majority consensus) to go back and modify history. In short Blockchain belongs to nobody and to anybody.
The success of this technology depends a lot on the governments; they have to be a part of this, they need to start issuing digital contracts, marriage certificates, passports, licenses, etc. Estonia happens to be the first country to welcome Blockchain technology, which is not a surprise because Estonia has been offering efficient online services to its citizens for more than a decade. World is waiting to experience the ripples of Blockchain experiment started by Estonia.