Blockchain

What is Blockchain?

A blockchain is a decentralized, digital ledger that records transactions across a network of computers. It is designed to be transparent, secure, and resistant to unauthorized changes.

How does Blockchain work?

1. Transactions are grouped into "blocks" and broadcast to the network.
2. Nodes verify these transactions using a "consensus mechanism" (like PoW or PoS).
3. Each block contains a cryptographic hash of the previous block, creating a chain.
4. Once a block is added, the data within it becomes immutable and nearly impossible to alter.
5. Every participant in the network maintains a synchronized copy of the entire ledger.

Why does Blockchain matter?

Blockchain enables "trustless" interactions, allowing people to exchange value or data without needing a central intermediary like a bank. It provides a permanent, auditable record that is secure against censorship and fraud.

Key features of Blockchain

• Decentralized (no single point of control)
• Immutable (data cannot be easily changed)
• Transparent (publicly verifiable)
• Consensus-driven (network-wide agreement)
• Secure (protected by cryptography)

Examples of Blockchain

• Bitcoin, the first and most secure blockchain for digital money.
• Ethereum, which added smart contracts to enable decentralized applications.
• Polygon and Arbitrum, which are "Layer 2" chains built to scale Ethereum.