This is the challenge for 
What is the blockchain? Among other things, it is one of the buzzwords of recent times. The chain of blocks is also a concept that raises a huge revolution not only in our economy, but in all kinds of areas.
Understanding what this chain of blocks is is not so difficult, and since this concept is being used more and more, we wanted to make a kind of quick introduction to the blockchain , to explain what it is, how it works and what is the revolution that it poses the chain of blocks.
Goodbye, sir (banker) intermediary
Let's get in situation. The normal thing is that if a person called for example Mariano wanted to send 1,000 euros to another person called for example Luis, it is normal for the transaction to be carried out through a bank. That bank acts as an intermediary of that and many other transactions , effectively centralizing the movement of capital from one side to the other.
Mariano would ask his bank to withdraw 1,000 euros from his account and transfer them to Luis' account: in just a few hours (depending on the bank, of course) that bank will have written down the transaction in his account , subtracting 1,000 euros from his account and communicating to the other bank that you must add 1,000 euros to Luis' account. Someone in Luis's bank (at this point, we already know that someone is a computer program) will note that in Luis's account there are 1,000 euros more coming from Mariano's bank account.
This management has not needed a transfer of bills from one place to another, but simply there has been one or two banks that have been responsible for making the money pass from one to another with a simple change in the balance of their accounts . Everything great and fantastic, except for one problem:
That neither Mariano nor Luis have any control over the process , of which only those banks have all the information. Both depend on those banks and their way of doing things to complete that transaction. They are subject to their conditions (and their commissions, of course).