What is Blockchain?

Blockchain is a decentralized digital ledger technology that records transactions across many computers. It's the core of Bitcoin and other cryptocurrencies, but its applications extend far beyond finance.

Blockchain_Structure
Think of it as a **linked list** of blocks, where each block contains a list of transactions and a cryptographic hash of the previous block. This creates an immutable chain of records.

Key Concepts

  • Decentralized Ledger: No single entity controls the entire network.
  • Public Key Cryptography: Uses cryptographic keys (public and private) for secure transactions.
  • Consensus Mechanisms: Protocols like Proof-of-Work (PoW) or Proof-of-Stake (PoS) validate transactions.
  • Smart Contracts: Self-executing contracts with terms directly written into code.
Public_Key_Cryptography

Bitcoin Overview

Bitcoin, the first cryptocurrency, uses blockchain to enable peer-to-peer transactions without intermediaries.

  • Blockchain: Stores all transaction data permanently.
  • Mining: Validates transactions and secures the network.
  • Wallets: Store private keys to access funds.
Bitcoin_Overview

Smart Contracts

These are automated agreements that execute when predefined conditions are met.

  • Use Cases: Automating insurance claims, supply chain tracking, or decentralized apps (dApps).
  • Platforms: Ethereum, Solidity, and more.
Smart_Contract

Blockchain Use Cases

  • Finance: Cryptocurrencies, DeFi platforms.
  • Healthcare: Secure patient data sharing.
  • Supply Chain: Transparent tracking of products.
  • Voting Systems: Immutable record of votes.
Blockchain_Applications

Conclusion

Blockchain offers revolutionary potential for transparency and security. To dive deeper, check our Blockchain Advanced Concepts tutorial!
📌 Tip: Explore how blockchain solves the double-spending problem in our Core Principles guide.