In this session we will briefly explain the concepts of blockchain (chain of blocks holding transactions) and blockchain networks (peer-to-peer networks of blockchain nodes, replicating a distributed ledger through a decentralized consensus algorithm).

We shall demonstrate how to write a simple educational blockchain network in JavaScript consisting of blockchain nodes (holding the chain and peers, using a consensus based on proof-of-work mining and exposing a RESTful API), along with a mining app (used to mine new blocks), a wallet app (used to manage private keys, sign and send transactions), and a faucet app to get testing coins.