A report: 1200 – 1500 words about Block chain

Blockchain is becoming more and more important trend recently. Using different academic papers, trusted website and conferences papers, the links should be attached in the reference section. Write a report and talk about this technology in 1200-1500 words. The report should address the following questions:

What is Block chain?

When was it started?

How it works?

What does a decentralize block chain mean?

What are the types of Block chain?

What are the fields where Block chain is used?

Real life cases of block chain