Learn the principles behind a blockchain by playing with this demo

How does a blockchain work?

This website (http://blockchaindemo.io/) helps you answer this question. You can play around with a simple blockchain demo in order to understand its underlying principles. (Ps.: I'm not the author of it.)

What you will learn with the demo

• What is a blockchain?
  It's simply a particular way to implement database. It's made of blocks of data chained together and maintained in a distributed way.
• What is a block?
  It's a piece of valuable information (data) and some other fields necessary for the implementation of the blockchain, like: previous hash, hash, timestamp, index and nonce.
• How blocks are chained together?
  Blocks are linked together by the previous hash field. New blocks are added to the database through a process called mining.
• What is mining and what it does?
  When you mine a new block, you add it to the central database by linking it to the existing last block. The very first block is called the Genesis Block.
• What are peers?
  A blockchain is distributed, which means people anywhere can connect to it. These people are called peers, as they can see (and some of them help maintain) the database and also interact with it, by creating new blocks. The data in a block is public to all peers.

Demo

The demo (http://blockchaindemo.io/) is a very intuitive way to help you internalize the blockchain model in your head. Once you play enough with it, you start to grasp the concepts faster and connect the dots on the different scenarios in which blockchains can be used.

Nevertheless, the demo is very simple and addresses only a small subset of the blockchain subject (it only addresses the abstraction model of the database).

That is why I put together a list of different topics not addressed by the demo. Each topic is followed with links to resources that explain it. Check below.

What you will not learn with the demo

• How mining works
  How bitcoin mining works - https://www.bitcoinmining.com/
  A simple explanation for mining - https://goo.gl/VYD38v
• How to start mining yourself
  An idiot's guide to building an ethereum mining rig - https://goo.gl/XPnEPa
  Life inside a secret chinese bitcoin mine - https://goo.gl/7GrLjC
• What is hashing?
  Hash Function (Wikipedia) - https://goo.gl/Eq4THR
  Bitcoin hash function explained - https://goo.gl/mSsqbD
• Why blockchains are important
  19 Industries The Blockchain Will Disrupt - https://goo.gl/kYgLwn
  Why blockchains will change the world - https://goo.gl/fHA9Pj
• How cryptocurrencies use blockchains
  How Bitcoin Works Under the Hood - https://goo.gl/LiLSGw
• How blockchains are used in different contexts (like smart contracts)
  Ethereum Vs. Bitcoin: What Sets Them Apart? - https://goo.gl/fYRFp3
  What is a Smart Contract? A Beginner’s Guide - https://goo.gl/fTgzRb
• How to code your own blockchain
  A blockchain in 200 lines of code - https://goo.gl/LYyWZr
  Open platform for blockchain applications - https://www.multichain.com/