Using cryptography to keep exchanges secure, blockchain provides a decentralised database, or “digital ledger”, of transactions that everyone on the network can see. This network is essentially a chain of computers that must all approve an exchange before it can be verified and recorded.
Learn more about the use of Blockchain in healthcare here:
It is distributed. Means it is de- centralised. Nobody is an owner.
It is public. Everyone can see it.
Things that have happened are time stamped, recorded and coded.
It is persistent. As far as everyone is participating, it is for forever.
SECURITY AND PRIVACY are built into the system as well. (On the internet the problem was that TCPIP is not built in for identity or encryption.
Smart contracts are built in- which means once a transaction is made automatically the laws of the contract are applied and executed. Value, data and money can be moved now.
For example, if everyone in a conference room has a spreadsheet of no. of shirts they own and they share it. The data miners after every 10 seconds will find out the new shirts added, shorts deleted, ownership of shirts changed, etc..
The miners will then publish this to everyone holding a ledger who participated in the blockchain. This is called block of work chained to the initial block and hence blockchain- that is why it is persistent, and you get a running, consistent account of things that is time stamped, verified by everyone, virtually un-hackable because no one can reverse it.
And this is the reason why for Bitcoins, financial services it is an important technology because this is why you wait for 3 days for your cheque to get cleared. Right!