What is blockchain in cryptocurrency?

What Is Blockchain in Cryptocurrency?

In cryptocurrency, the blockchain is the shared digital ledger that records every transaction. Think of it as a chain of blocks: each block holds a set of transactions, a timestamp, and a link to the block before it. Once a block is added, changing past data becomes practically impossible without changing all later blocks, which the network rejects.

How Blocks Are Added

Nodes (computers on the network) collect new transactions and bundle them into a block. How that block is accepted depends on the cryptocurrency. In Bitcoin, miners solve a cryptographic puzzle (proof of work). In Ethereum and many newer chains, validators stake coins and vote (proof of stake). When the network agrees, the block is added and the chain grows.

Key Properties

• Decentralization: Many copies of the ledger exist. No single entity can rewrite history.
• Transparency: On public blockchains, anyone can view transactions and balances.
• Immutability: Past records are extremely difficult to alter.

Why It Matters for Crypto

Blockchain is what allows cryptocurrency to work without a central bank or company. It ensures that the same coin cannot be spent twice and that everyone agrees on who owns what. Understanding blockchain helps you see how crypto is different from ordinary digital money.