Blockchain

A decentralized digital ledger that securely records transactions across a network of computers in an immutable chain.

What is Blockchain?

A blockchain is a decentralized, distributed digital ledger that records transactions with a network of computers (nodes) in a secure, transparent, and tamper-resistant manner. Each transaction is grouped into a block, cryptographically linked to the previous one, forming a chronological chain. Initially developed for Bitcoin in 2008 by Satoshi Nakamoto, blockchains use consensus algorithm like proof-of-work(PoW) or proof-of-stake(PoS) to validate data without a central authority.

Public blockchains, such as Ethereum and Solana are open, permissionless networks where anyone can participate as a node. Ethereum powers smart contracts, DeFi, NFTs, and DAOs via its Ethereum Virtual Machine (EVM); Solana offers high-speed, low-cost transactions for scalable dApps and Web3 ecosystems.

In contrast, private blockchains restrict access to authorized participants, often used by enterprises for internal processes with enhanced privacy and control (e.g., Hyperledger Fabric). Consortium blockchains, a hybrid model, are governed by a group of organizations, balancing decentralization with restricted access for use cases like supply chain or banking (e.g., R3 Corda).

As of 2025, public blockchains process trillions in transactions annually, driving global adoption in finance, gaming, and digital ownership, while private and consortium chains cater to specialized, permissioned applications.