How would you explain blockchain technology to a layman? How is it decentralized?

How do you explain blockchain technology to a layman? How is it decentralized?

Blockchain
Studying blockchain at first will cause a bit of confusion. Just like the beginning I studied blockchain is quite confusing. Here I will give a little reference for my friends to start studying blockchain one of the technologies behind the fast development of Cryptocurrency in the world. Here I will try to discuss this blockchain as easy as possible, because blockchain is actually a simple and simple technology.

introduction
Basically in the field of technology activities carried out is data processing, and in the processing of data that many elements - elements in it such as where the data is placed, how data is made, how the data is distributed and others.

As we know at this point any data that we are centralized or only stored in a single computer we call the server. The current system has many disadvantages, one of which is data security is not maximal because the data is only located in one place where it makes our data can not validate the data. The other is a problem if there is a system failure of the server will make the network down if we do not have a backup then it loses the data we have.
so for beginners or a layman about blockchain follow me