2/ Key features:
- Decentralized: No single point of control
- Immutable: Transactions are permanent & can't be altered
- Transparent: All transactions are publicly visible
- Secure: Cryptographic algorithms protect the network #BlockchainTech

3/ Use cases:
- Cryptocurrencies: Secure, decentralized transactions
- Supply Chain: Track & verify product movement
- Smart Contracts: Automate agreements & transactions
- Identity Verification: Secure digital identities #BlockchainApplications