Blockchain

Basics

In short A shared, append-only ledger maintained by many computers. Once recorded, entries are practically impossible to alter, which is what makes on-chain assets trustworthy without a central operator.

Blocks are batches of transactions, each one carrying a fingerprint of the block before it. Change an old record and every fingerprint after it stops matching, so rewriting history means redoing all the work that followed — which is why the chain is treated as settled rather than merely stored. Different networks reach agreement differently (Bitcoin spends computing power, Ethereum stakes capital), but the guarantee is the same: no single operator decides what the record says.

Learn this properly The Beginner’s Guide covers this in context