Blockchain
What is Blockchain?
A shared, append-only ledger that records transactions in linked blocks.
Understanding Blockchain
A blockchain stores records in blocks, each linked to the one before it with a cryptographic hash. Changing an old record would mean rewriting every block after it.
Copies of the ledger are kept by many computers, which agree on new blocks through a consensus method such as proof of work or proof of stake.
FAQ
Is every blockchain public?
No. Public blockchains let anyone participate; private or permissioned ones limit who can add records.