1. Introduction

The Oracle Problem

• Blockchains can't interact with real world data and events

Oracles

• Any device that interacts with off chain world to provide external data or computation to smart contracts

• We need decentralized oracle network

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Smart Contracts

An agreement, contract or set of instructions that is deployed on a decentralized blockchain.

A smart contract is

• Cannot be altered (immutable)

• Automatically executes

• Everyone sees terms of agreement

Hybrid Smart Contracts

• Combining off chain decentralized logic with off chain decentralized data and decentralized computation gives rise to hybrid smart contracts

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Chainlink

• It is a decentralized oracle network

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Versions of Web

Web1

The permissionless open sourced web with static content

Web2

The permissioned web, with dynamic content. Where companies run your agreements on their servers

Web3

The permissionless web with dynamic content. Where decentralized censorship resistant networks run your agreement and code.

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Basic Terminologies

DeFi

• Stands for Decentralized Finance

DAOs

• Stands for Decentralized Autonomous Organizations

NFTs

• Stands for Non Fungible Tokens

Consensus

• Mechanism used to agree on state of blockchain

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