Blockchain Ethereum Fundamentals

What is Ethereum?

Ethereum is a programmable blockchain that enables developers to create decentralized applications (dApps). Unlike Bitcoin, which mainly handles transactions, Ethereum supports smart contracts—code that runs automatically under certain rules.

Core Concept

Ethereum acts as a worldwide digital computer, where people can write and store logic-driven scripts. These scripts live forever on-chain and control how assets, access, or services behave.

Ether (ETH)

Ether is Ethereum's built-in currency

It is used to pay for transactions, storage, and computational power

Works as fuel for smart contract operations (also called "gas")

Ethereum Virtual Machine (EVM)

EVM is the runtime that executes code written for Ethereum

Think of it as a sandbox that runs decentralized software globally

Converts smart contract code into machine-readable instructions

Smart Contracts

Self-executing code blocks deployed to Ethereum

Conditions drive outcomes without manual steps

Cannot be modified once launched

Powers NFTs, tokens, games, DAOs, and much more

dApps (Decentralized Applications)

• Applications that run peer-to-peer without relying on centralized servers
• Commonly used in finance, gaming, social platforms, and marketplaces
• Built using tools like Solidity, Web3.js, and Truffle

Gas & Transactions

Every operation on Ethereum consumes gas, a measure of computing effort

Users pay gas fees in ETH to execute actions

Gas prices depend on network activity and demand

Ethereum Tools & Ecosystem

• Solidity: Programming language for writing contracts
• Remix IDE: Browser-based platform for testing smart contracts
• Metamask: Wallet for interacting with Ethereum-based dApps
• Infura: Infrastructure provider for Ethereum APIs
• Ganache: Local blockchain simulation for testing

Public, Open, and Global

• Ethereum welcomes all—no gatekeepers, no approvals, just open innovation for everyone.
• Updates and upgrades are proposed through Ethereum Improvement Proposals (EIPs)
• Powered by global miners or validators (depending on PoW or PoS)

From Proof-of-Work to Proof-of-Stake

Originally used Proof-of-Work (PoW) for security

Ethereum 2.0 now runs on Proof-of-Stake, shifting power from miners to validators for energy-efficient consensus.

Stakers lock up ETH to secure the network instead of mining