What is Blockchain?

Blockchain: a crypto term, explained in plain English.

In one line

A shared record of transactions, copied across many computers, where each new block of entries is linked to the one before it.

Crypto Reviewed by Keshav Aggarwal · Updated 4 Nov 2026

In simple words

Imagine a class notebook that every student has an exact copy of. When someone writes a new line, everyone adds the same line to their copy.

Nobody can secretly rub out an old line, because everyone else’s copy would show the change. That shared notebook is a blockchain.

The technical side

A blockchain is a ledger made of blocks, each holding a batch of transactions and a cryptographic hash of the previous block, so changing an old entry breaks every block after it. Thousands of independent computers (nodes) keep copies and agree on the next block through a consensus method such as proof of work or proof of stake.

Bitcoin, described in a 2008 paper by Satoshi Nakamoto and launched in January 2009, was the first working blockchain. Ethereum, Solana and many others followed.

Blockchain kya hai?

Blockchain ek aisi notebook hai jiski copy hazaaron computers ke paas hoti hai. Ek baar entry likh di, toh koi chupke se mita nahi sakta.

Not investment advice. Crypto tokens can lose all their value. Read the risk disclaimer.

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