Last Updated: November 21, 2025
Blockchain Basics
Decentralized ledger technology fundamentals
Key Concepts
| Item | Description |
|---|---|
Block
|
Container of transactions with hash |
Chain
|
Linked sequence of blocks |
Hash
|
Cryptographic fingerprint of data |
Consensus
|
Agreement mechanism (PoW, PoS) |
Node
|
Computer in the network |
Mining
|
Process of validating transactions |
Blockchain Components
- Block Header: Contains metadata (timestamp, previous hash, nonce)
- Block Body: Contains transaction data
- Genesis Block: First block in the chain
- Merkle Tree: Efficient transaction verification structure
- Digital Signatures: Verify transaction authenticity
Consensus Mechanisms
| Item | Description |
|---|---|
Proof of Work (PoW)
|
Mining-based, energy intensive |
Proof of Stake (PoS)
|
Stake-based, energy efficient |
Delegated PoS
|
Voted validators |
Proof of Authority
|
Identity-based validators |
Byzantine Fault Tolerance
|
Voting-based consensus |
Use Cases
- Cryptocurrency: Digital money transfers
- Smart Contracts: Self-executing agreements
- Supply Chain: Track product authenticity
- Healthcare: Secure medical records
- Voting: Transparent election systems
- Real Estate: Property title management
💡 Pro Tips
Quick Reference
Foundation of cryptocurrency and decentralized applications