Blockchain Basics

Proof of History (PoH, Solana) A Solana innovation: cryptographic clocks to order transactions before consensus. TL;DR: PoH timestamps transactions with a verifiable delay function (VDF). This makes consensus faster because order is already established. In practice, Solana runs a sequential hash chain (a “cryptographic clock”) that proves the passage of time. Leaders mix incoming transactions […]

Proof of Authority (PoA) Consensus where trusted authorities validate blocks instead of open participation. TL;DR: Validators are pre-approved (often identity-verified) and take turns proposing/validating blocks using a Byzantine Fault Tolerant (BFT) engine (e.g., Clique, IBFT). This delivers fast finality and low fees but concentrates power in a small, permissioned set. Security derives from institutional accountability

Delegated Proof of Stake (DPoS) A variation of Proof of Stake where token holders elect delegates (validators). TL;DR: Token holders vote for a small set of delegates who validate blocks. Fast, efficient, but introduces political risks. DPoS trades a broad validator set for a rotating committee elected by stake; performance rises, but the system must

Consensus Mechanisms: Proof of Work vs Proof of Stake How networks agree on truth without a central authority, energy vs stake, miners vs validators. TL;DR: Proof of Work (PoW): miners burn electricity to secure the chain. Attacking requires massive energy & hardware. Proof of Stake (PoS): validators lock tokens (“stake”) to earn rewards. Attacking risks

Gas Fees Explained (2025): Why Transactions Cost Money — and How to Pay Less Beginner → Intermediate Blockchain Basics • ~18–25 min read • Updated: 2025-11-07 TL;DR: Gas exists to price scarce block space and keep networks spam-resistant. On post-EIP-1559 Ethereum, each tx pays for gas used × (base fee + priority tip): the base

Public & Private Keys Explained (Wallet Addresses, Seed Phrases, Signatures) Beginner → Intermediate Wallets & Security • ~14–16 min read • Updated: 2025-11-07 TL;DR: Your private key is a secret 256-bit number that controls an account. The public key is derived from it by a one-way operation (elliptic-curve multiplication). Your address is a short, shareable

What Is a Blockchain? A Complete Beginner-to-Builder Guide (with Diagrams) Beginner Blockchain Basics Hands-on • Updated: 2025-11-07 TL;DR: A blockchain is a public, append-only database that many independent computers (nodes) keep in sync. Transactions are batched into blocks. Each block points to the previous block’s hash (a tamper-evident fingerprint), forming a chain. A consensus protocol