DLDevLadder📒 My Notebook
Roadmap › 6. Web3 & Blockchain › Step 55
W3

Blockchain & Web3 Fundamentals

Web1/Web2/Web3, blockchain data structures, hashing and cryptography, consensus (PoW, PoS), Bitcoin and Ethereum, accounts, transactions and gas, wallets and keys, tokens (ERC-20, ERC-721, ERC-1155), DeFi, NFTs, DAOs, layer 2s, oracles, dApp architecture with .NET and JavaScript, and security.
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Core terms

Block · hash · Merkle root · node · consensus · mempool · confirmation · finality · fork · wallet · private/public key · address · seed phrase · gas · nonce · smart contract · EVM · ABI · token · dApp · oracle · bridge · L1/L2.

Consensus

PoW (Bitcoin, mining) · PoS (Ethereum since Sep 2022, staking, slashing, 32 ETH validator, 12 s slots, ~12.8 min finality) · DPoS · BFT · PoA.

Bitcoin vs Ethereum

BTC: 2009, PoW, 10-min blocks, 21M cap, UTXO, halving every ~4 years. ETH: 2015, PoS, 12-s blocks, account model, smart contracts, 1 ETH = 10^18 wei, EIP-1559 fee burn.

Token standards

ERC-20 fungible · ERC-721 NFT · ERC-1155 multi-token · ERC-4626 vaults · ERC-2612 permit · ERC-4337 account abstraction · EIP-712 typed signing · ERC-4361 Sign-In with Ethereum.

Scaling

Optimistic rollups (Arbitrum, Optimism, Base — 7-day challenge) · ZK rollups (zkSync, Starknet, Scroll, Linea) · sidechains (Polygon PoS) · Lightning (BTC) · EIP-4844 blobs (2024).

Upgrades to remember

The DAO hack 2016 · EIP-1559 2021 · The Merge 2022 · Shanghai 2023 · Dencun 2024 · Pectra May 2025 · Fusaka Dec 2025.

Dev stack

Solidity · Hardhat / Foundry / Remix · OpenZeppelin · ethers.js v6 / viem / wagmi · Nethereum (.NET) · MetaMask · Infura/Alchemy · Etherscan · Sepolia testnet · IPFS · The Graph · Chainlink.

Security

Seed phrase = ownership · limit approvals · audits · reentrancy · oracle manipulation · flash loans · bridge risk · MEV · multisig + timelock admins.