Overview
A blockchain is a distributed ledger system designed to record units of digital information—known as blocks—consecutively and securely in an immutable database. It serves as the foundational architecture for cryptocurrencies, smart contracts, and decentralized applications.
Core Characteristics
- Sequential Block Linking: Data is packaged into blocks that are attached chronologically, creating a permanent and audit-ready historical record.
- Decentralization: Information is replicated across a network of independent computers (nodes), eliminating single points of failure and central control.
- Public vs. Private Access:
- Public Blockchains: Permissionless, transparent networks open to any participant (e.g., Bitcoin, Ethereum).
- Private Blockchains: Permissioned networks utilized by enterprises, financial institutions, and governments for tailored operational use cases.
Broader Ecosystem Role
Beyond digital money, blockchain technology enables a wide range of Web3 innovations, including self-custody wallet infrastructure, automated agentic transactions, and decentralized finance (DeFi) protocols.