What is Block chain?

Question

what it is,where to use ,field and application.
future demand of block chain

Answer 1

A very good question and a very broad question as well. Well I will keep it short and simple.
"Block chain", as its name suggests; it's a chain of blocks of information. But what information exactly it holds? Right? Imagine you are going to buy a car. So you of course need some information about it before you buy it. Like, what it's cost, who was its previous owner, what condition it is in..... etc. And the seller do have the record of it. It's called a "Ledger". And when you are going to sell the same car you will update more information in the same Ledger. And this process goes on. But you can imagine anyone can tamper some of the records in that Ledger and try to cheat the next buyer.
This is where Block Chain gets its grand entry. No one (I repeat No one) can ever mess with any records in a Block Chain Ledger. Because, its architecture prevents to do so. How? By 2 major weapons,
1. The whole algorithm doesn't run on a single computer. It's a distributed computing algorithm. So the record needs to get tampered in every computer in the network which is near impossible.
2. Encryption: Encryption of whole Ledger even makes the above task even more difficult.

Answer 2

Many people don't understand. It's the next biggest invention of humanity after machine, electricity and Internet.