What is a blockchain?

What kind of beast is this "blockchain" and will it replace the real financial system.

What is blockade?
This is one of the types of decentralized data storage in which block chains are used.
This can be compared with a diary in which each line is a block, and the diary itself is stored and maintained by a large number of computers.

Why do we need such happiness?

In order to store the history of database changes with absolute transparency.

How to use?

Imagine, Vasya owes you $ 1000. Of course, you did not take a receipt, or, as always, took it, but forgot where, put it, and you do not have witnesses, either. After a while Vaska drew. And he said it was all nonsense, and you dreamed everything. In the end, you stayed with your nose, and Vasya with your money. It is in this case that the need for blockage is so great. After all, millions of blocks will testify to your transactions. Vasek, your friend, will not suffer from amnesia.

On a note
I'm not sure if the block will replace the real financial system, but it will surely replace what each of us needs: confidentiality, transparency and accuracy.