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What is a Blockchain?

  • A data structure
  • Typically an ordered, back-linked list of blocks with data.
  • Each block is identified by a hash
  • The hashes protect the integrity of the data

Typically, the blocks in a blockchain contain blockheaders and a payload

Although the payload could be any arbitrary data, it is mainly used for

  • Record keeping - who, what, when, and why (ex: ledgers)
  • Self-executing code (ex: smart contracts)
  • Hashes of arbitrary data (ex: hashes of Images, videos as NFTs)

Introduction to Blockchain

A Few Definitions of Blockchain

"Blockchain is a shared, immutable ledger for recording transactions, tracking assets and building trust." - IBM

"Cryptocurrencies like Bitcoin and Ethereum are powered by a technology called the blockchain. At its most basic, a blockchain is a list of transactions that anyone can view and verify." - Coinbase

"Blockchain technology is an advanced database mechanism that allows transparent information sharing within a business network. A blockchain database stores data in blocks that are linked together in a chain. The data is chronologically consistent because you cannot delete or modify the chain without consensus from the network. As a result, you can use blockchain technology to create an unalterable or immutable ledger for tracking orders, payments, accounts, and other transactions. The system has built-in mechanisms that prevent unauthorized transaction entries and create consistency in the shared view of these transactions." - Amazon AWS

Is Blockchain a scam?

  • Blockchain and cryptography are the safeguards against scams and forgery
  • Get a few obvious misconceptions out of the way
  • Highlight the need for education and awareness

Are Blockchains Decentralized?

  • The power of redundancy
  • Distributed vs Decentralized
  • Decentralization is a spectrum
  • The power of decentralization

Centralization vs Decentralization

Types of Blockchains

  • Public blockchain networks
  • Private blockchain networks
  • Permissioned blockchain networks
  • Consortium blockchains

Blockchains in Action

  • Bitcoin
  • Ethereum
  • Polkadot

Run your own Blockchain!

For tech savvy learners

  • Walkthrough of Substrate Node Template