In the year 2017, Bitcoin touched a market capitalization of over 100 billion dollars. In the year 2014, one Bitcoin could buy about 500 dollars, just three years later one Bitcoin buys 5,000 dollars. The Initial Coin offering is becoming the preferred method of raising money. Many countries like Dubai have announced their own cryptocurrency called emCash.

Bitcoin, Ethereum, Blockchain are the most difficult technologies to understand. That's why most people including technology folks cannot understand the future direction of these technologies. The only way to understand anything complex is by going back to the basics.

This is what we do in this book. We explain every byte of the Bitcoin blockchain that is downloaded on your computer. only by going back to your roots can you understand anything complex.

Most of the code in this book is written in Python as today, it is the easiest language to use. The Bitcoin Source is written only in C++. Most of the important Bitcoin data structures are only documented in code, a bare knowledge of reading and not writing C++ will help. Finally,  the official client for Ethereum is written in the programming language Go.

It is written for a programmer, We use code and not words to describe a blockchain. We believe that all kinds of people including non-technology folks will need some programming knowledge to grasp the basic concepts of the blockchain. There is no other way to understand this technology.

Finally, we end the book with the biggest use of smart Contracts which is raising money using an ICO. Our primary focus is on Bitcoin and Blockchains and not on Ethereum and smart contracts which comprises only 4 chapters.

International Currency transfers are very expensive today. With the advent of the Lightning Network and sidechains, the Bitcoin blockchain can scale to a level where it can handle transactions faster than any credit card transaction.

One of the recent bigger innovations of Blockchain technology is the Initial Coin offering or an ICO. This will enable millions of people to invest in companies using blockchain technology. This will help us understand the technologies under the hood that makes it happen.