What Is Blockchain?
Blockchain is a decentralized digital ledger that records transactions or data in a chain of cryptographically linked blocks, ensuring transparency, security, and immutability without relying on any central authority. [6]
How Blocks Link Together
Each block contains a batch of transactions and a cryptographic pointer to the previous block.
Real-World Applications
Cryptocurrency
Peer-to-peer digital currencies like Bitcoin and Ethereum remove the need for banks.
Supply Chain
Track goods from origin to delivery with full transparency and auditability.
Smart Contracts
Self-executing agreements encoded in code, triggering automatically when conditions are met.
Blockchain History Timeline
The idea started with timestamped documents in 1991, progressed through cryptographic innovations in 2004, saw Bitcoin’s white paper in 2008 and launch in 2009, and evolved into smart-contract platforms like Ethereum by 2015. [6][7][8]
Sources
- [6] GeeksforGeeks. “History of Blockchain.” https://www.geeksforgeeks.org/software-engineering/history-of-blockchain/
- [7] AmityOnline. “History of Blockchain: A Complete Timeline from 1990s to 2025.” https://amityonline.com/blog/blockchain-history-from-bitcoin-to-now
- [8] Harvard Business Review. “A Brief History of Blockchain.” https://hbr.org/2017/02/a-brief-history-of-blockchain
- [14] 101 Blockchains. “Best Blockchain Infographics Collection.” https://101blockchains.com/blockchain-infographics/