Blockchain

Key points

• Blockchain is a distributed digital ledger that records transactions in chained blocks, maintained by many computers at the same time.
• Each block references the previous one through a cryptographic digest, which makes the history resistant to alteration once confirmed.
• By removing the need for a central authority, it allows value to be transferred between parties who don't need to trust a single intermediary.

What is a blockchain?

Blockchain is a shared digital record that organizes transactions into blocks linked in chronological sequence. Every participant in the network keeps a copy of this record, and consensus rules define how new blocks are added. The result is a public history that no single party controls and that is hard to rewrite.

How it works

Transactions are grouped into a block and validated according to the protocol's rules. Each block carries the output of a hash function applied to the previous block, creating a chain: changing an old piece of data would require redoing every subsequent block across every copy of the network, something unfeasible on large chains.

To decide who adds the next block, networks use consensus mechanisms. In proof of work, participants spend computational power to solve a cryptographic problem. In proof of stake, validators are chosen based on the amount of assets they commit. In both cases, the goal is to make attempting to defraud the ledger costly.

Once confirmed and buried under new blocks, a transaction becomes practically irreversible. This combination of distribution and cryptographic chaining is what gives blockchain its core property: practical immutability.

Why it matters

Blockchain is the infrastructure on which stablecoins, smart contracts, and on-chain payments run. For a business settling amounts in crypto, it offers an auditable record available at any time, without depending on the hours of a central banking system. This is the foundation that allows value to move between countries programmatically. Networks like Solana and those compatible with the Ethereum virtual machine settle transactions in seconds and at low cost, which makes payments at scale viable and explains why international corridors have started using public blockchains as a settlement rail.

Risks and limitations

Small chains, with little validation power, are more vulnerable to attacks that reorganize recent blocks. In addition, immutability has a cost: transactions sent by mistake cannot be undone. Processing capacity is also limited, which can raise fees during periods of congestion.