Key Features of Blockchain:

1. Decentralization: Unlike traditional systems that rely on a central authority (like a bank or government), blockchain operates on a peer-to-peer network where multiple participants (nodes) maintain and verify the ledger.
2. Immutability: Once data is recorded in a block and added to the chain, it becomes extremely difficult to change. This provides a high level of security and trust since transactions cannot be easily altered or tampered with.
3. Transparency: Transactions on a blockchain are visible to all participants in the network, making it highly transparent. Each participant can view and verify the entire transaction history.
4. Security: Blockchain uses cryptographic techniques to secure the data. Every block contains a unique code, called a hash, and links to the hash of the previous block, making it difficult for unauthorized parties to alter the information.
5. Smart Contracts: These are self-executing contracts with the terms of the agreement written directly into code. They automatically execute actions when predetermined conditions are met, eliminating the need for intermediaries.

Applications of Blockchain:

• Cryptocurrency: Blockchain is the foundation of digital currencies like Bitcoin, Ethereum, and many others. It records cryptocurrency transactions securely without needing a central authority.
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• Supply Chain Management: Blockchain ensures the traceability of products from origin to consumer, improving transparency in supply chains.
• Finance: It allows for faster, more secure transactions, reducing the need for intermediaries like banks, while lowering transaction costs.
• Healthcare: Blockchain can securely store and share medical records across institutions while maintaining patient privacy.
• Voting: Blockchain can be used to create secure, tamper-proof voting systems, ensuring that elections are transparent and verifiable.

In essence, blockchain technology provides a way to record and track transactions or data in a highly secure, transparent, and decentralized manner.