Blockchain Technology 

Blockchain is a decentralized, distributed ledger technology (DLT) that records transactions across many computers so that the records cannot be altered retroactively without the consensus of the network. It ensures transparency, security, and trust in digital transactions.

Key Features of Blockchain:

1. Decentralization:
   No single central authority controls the data; it’s maintained by a distributed network of nodes.

2. Immutability:
   Once data is written to a block and added to the chain, it cannot be changed or deleted.

3. Transparency:
   Transactions on public blockchains are visible to all participants and can be audited in real-time.

4. Consensus Mechanisms:
   Blockchain uses algorithms like Proof of Work (PoW), Proof of Stake (PoS), or others to agree on data validity.

5. Security:
   Transactions are encrypted and linked to previous blocks, making tampering extremely difficult.

 How It Works:

1. A transaction is requested.

2. The transaction is broadcast to a peer-to-peer (P2P) network.

3. The network of nodes validates the transaction using a consensus mechanism.

4. A new block representing the transaction is created.

5. The new block is added to the existing blockchain.

6. The transaction is complete and recorded permanently.

Applications of Blockchain:

• Cryptocurrency (e.g., Bitcoin, Ethereum)

• Supply Chain Management

• Healthcare Records

• Voting Systems

• Digital Identity Verification

• Smart Contracts (self-executing contracts with code-based rules)

Benefits:

• Increased transparency

• Enhanced security

• Reduced costs by eliminating intermediaries

• Faster and automated transactions

Challenges:

• High energy consumption (especially PoW)

• Scalability issues

• Regulatory uncertainty

• Technical complexity