We've focused on organizing the book to fit business and IT beginners in blockchain technology. The chapters are arranged to ensure that they can be followed easily and flow naturally.

Business users can skip the chapters with detailed descriptions on how to develop blockchain applications and, instead, focus on the chapters with general descriptions of the technology and use cases.

Veteran IT professionals on blockchain can skip the general description chapters and focus on chapters either on Ethereum or Hyperledger, from which they will gain insights on how to build blockchain applications.

It is recommended that IT users download the code and make modifications for adopting to their own use cases or exercises.

You can download the example code files for this book from your account at www.packt.com. If you purchased this book elsewhere, you can visit www.packt.com/support and register to have the files emailed directly to you.

You can download the code files by following these steps:

1. Log in or register at www.packt.com.
2. Select the SUPPORT tab.
3. Click on Code Downloads & Errata.
4. Enter the name of the book in the Search box and follow the onscreen instructions.

Once the file is downloaded, please make sure that you unzip or extract the folder using the latest version of:

• WinRAR/7-Zip for Windows
• Zipeg/iZip/UnRarX for Mac
• 7-Zip/PeaZip for Linux

The code bundle for the book is also hosted on GitHub at https://github.com/PacktPublishing/Blockchain-Quick-Start-Guide. In case there's an update to the code, it will be updated on the existing GitHub repository.

We also have other code bundles from our rich catalog of books and videos available at https://github.com/PacktPublishing/. Check them out!

There are a number of text conventions used throughout this book.

CodeInText: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: "One important interface is ChaincodeStubInterface, which provides functions that allow you to query, update, and delete assets in the ledger."

A block of code is set as follows:

contract SimpleStorage {
    uint storedData; // State variable
    //…
}

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

pragma solidity ^0.4.15;
import 'zeppelin/contracts/math/SafeMath.sol';
….
contract ExampleCoin is ERC20 {
  //SafeMath symbol is from imported file SafeMath.sol'
  using SafeMath for uint256;
   …
}

Any command-line input or output is written as follows:

mkdir ~/insurance-claim && cd ~/insurance-claim

Bold: Indicates a new term, an important word, or words that you see onscreen. For example, words in menus or dialog boxes appear in the text like this. Here is an example: "When the preceding request is validated by mining nodes, the HelloWorld smart contract is invoked."