Blockchain Ethereum Explained

Bitcoin proved that a decentralized currency could work. Ethereum asked a more ambitious question: what if a blockchain could run any kind of program? Launched in 2015, Ethereum extended the blockchain concept into a globally accessible, decentralized computing platform. Today, Ethereum hosts thousands of applications, holds billions of dollars in financial protocols, and forms the foundation of the decentralized internet.

What Is Ethereum?

Ethereum is a decentralized blockchain platform that enables developers to build and deploy smart contracts and decentralized applications (DApps). Its native currency, Ether (ETH), powers all operations on the network. Vitalik Buterin proposed Ethereum in 2013. A team of co-founders built and launched it on July 30, 2015.

The simplest way to understand Ethereum: Bitcoin is a calculator (designed to do one thing very well — transfer value). Ethereum is a smartphone (it runs apps built by anyone for any purpose).

Key Differences: Bitcoin vs Ethereum

The Ethereum Account Model

Unlike Bitcoin's UTXO system, Ethereum uses an account-based model — similar to a traditional bank account. Every Ethereum address has a balance that updates directly after each transaction. No need to track individual coin chunks.

ETHEREUM ACCOUNT TYPES

1. Externally Owned Account (EOA)
   - Controlled by a private key
   - Represents a regular user's wallet
   - Can send ETH and trigger contract calls
   
   Example:
   Address: 0xPriya...
   Balance: 2.5 ETH
   Nonce:   14 (number of transactions sent)

2. Contract Account
   - Controlled by smart contract code
   - Has no private key
   - Executes code when triggered by a transaction
   
   Example:
   Address: 0xUniswapContract...
   Balance: Holds pooled ETH from liquidity providers
   Code:    Swap logic, fee distribution logic

The Ethereum Virtual Machine (EVM)

The Ethereum Virtual Machine (EVM) is a sandboxed computing environment that runs smart contracts. Every full node on Ethereum runs the EVM. When a user triggers a smart contract, every node runs the same code independently. All nodes must reach the same result — this agreement is how Ethereum confirms correct execution.

ETHEREUM TRANSACTION FLOW (Smart Contract Call)

User (via wallet) sends transaction to Contract Address
         |
         v
Transaction enters mempool (waiting area)
         |
         v
Validator selects transaction, includes in block
         |
         v
EVM on every node executes the contract code
         |
         v
All nodes agree on result
         |
         v
Result recorded permanently on Ethereum blockchain

Gas – The Fuel of Ethereum

Gas is the unit that measures computational effort on Ethereum. Every operation a smart contract performs — adding two numbers, storing data, transferring tokens — costs a specific amount of gas. Users pay for gas in ETH. Gas fees compensate validators for processing transactions.

Why Gas Exists

Without gas, a malicious user could deploy an infinite loop in a smart contract, consuming all network resources indefinitely. Gas sets a computational budget for each transaction. When gas runs out, the transaction stops, the changes revert, and the user loses the gas spent. This makes denial-of-service attacks economically costly.

Gas Fee Calculation

Total Fee = Gas Units Used × (Base Fee + Priority Fee)

Base Fee:     Set by network, automatically adjusts with demand
Priority Fee: Optional tip to prioritize faster inclusion

Example:
  Simple ETH Transfer: 21,000 gas units
  Base Fee: 30 Gwei (Gwei = 0.000000001 ETH)
  Priority Fee: 2 Gwei (tip)

  Total: 21,000 × (30 + 2) Gwei
       = 21,000 × 32 Gwei
       = 672,000 Gwei
       = 0.000672 ETH
       ≈ ₹240 (at current ETH price)

Complex DeFi Swap: 200,000+ gas units (costs proportionally more)

EIP-1559 – The Fee Burn Mechanism

In August 2021, Ethereum implemented EIP-1559, which changed how gas fees work. The base fee no longer goes to validators — it gets burned (permanently removed from circulation). Only the priority fee (tip) goes to validators. This burning mechanism makes ETH deflationary during high-usage periods — more ETH is burned than created through staking rewards.

BEFORE EIP-1559:
User pays full fee --> Miner receives full fee

AFTER EIP-1559:
User pays Base Fee + Priority Fee
  Base Fee --> BURNED (ETH removed from supply forever)
  Priority Fee --> Validator receives as tip

High network usage = More ETH burned = Supply decreases
This can make ETH deflationary

Ethereum's Major Upgrades

Ethereum's Ecosystem

ETHEREUM ECOSYSTEM OVERVIEW

LAYER 0 (Infrastructure)
  Internet, node hardware, validator infrastructure

LAYER 1 (Ethereum Mainnet)
  ETH coin, smart contracts, EVM, consensus (PoS)

LAYER 2 (Scaling Solutions)
  Arbitrum, Optimism, Polygon, Base, zkSync
  (Faster + cheaper, settle security back to Ethereum)

APPLICATIONS (DApps)
  DeFi:    Uniswap, Aave, Compound, MakerDAO
  NFTs:    OpenSea, Blur, Foundation
  Gaming:  Axie, Gods Unchained, Sorare
  DAOs:    MakerDAO, Compound, ENS
  Identity: ENS (Ethereum Name Service)

Layer 2 Solutions – Making Ethereum Faster

Ethereum processes approximately 15-30 transactions per second on its base layer. This is not enough for global adoption. Layer 2 (L2) solutions batch thousands of transactions off-chain and submit compressed proofs to Ethereum, inheriting Ethereum's security while dramatically increasing throughput.

Summary

• Ethereum is a programmable blockchain that runs smart contracts and DApps
• ETH is the native coin — used for gas fees and staking
• Ethereum uses an account-based model (not UTXO like Bitcoin)
• Gas measures computational effort; gas fees compensate validators
• EIP-1559 burns base fees, making ETH deflationary during high usage
• The Merge (2022) switched Ethereum to Proof of Stake — 99.95% energy reduction
• Layer 2 solutions process thousands of transactions cheaply while using Ethereum's security