What is a Blockchain?

Blockchains have been around forever, they are relatively simple pieces of computer code.

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Blockchains are ledgers

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Thye are a chain of blocks of information

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The blocks are chained together using math, you can’t alter one block without also altering all the other blocks

Uses for Blockchains

Walmart uses blockchains for keeping track of where each food product came from. Each time a paticular batch of oranges goes through a checkpoint the barcode on that batch is scanned. If a customer gets sick from an orange they can track that batch of oranges all the way back to its origin instantly because all that information is stored on a blockchain

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That use of a blockchain is quite different from bitcoin though. The difference is whether the blockchain is public or private. Walmart doesn’t need to broadcast to the whole internet the path of each food item, so they keep their blockchain private, only people in their company can access it. The bitcoin blockchain is public, and that’s where the invention was, combining blockchains with cryptography so the blockchain could be public.

The Bitcoin Blockchain

The bitcoin blockchain is a global, decentralized, immutable ledger.

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It’s global because anyone with internet access, anywhere in the world, can interact with the bitcoin blockchain.

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It’s decentralized because no one controls it. There’s a protocol (a set of rules written in computer code) that no one can change no matter how much money you have.

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It’s immutable like any blockchain. That’s the whole point of blockchains, once you add information to a blockchain it’s in there. You can’t change it.