What is Blockchain
A blockchain is a shared database where records are grouped into blocks and each block is cryptographically linked to the one before it.
In depth
Picture a notebook where every page ends with a fingerprint of the previous page. If someone alters an old page, its fingerprint changes and every page after it no longer matches — the tampering is instantly obvious. Because thousands of computers hold identical copies of this notebook, changing history would require convincing most of them at once.
Why it matters
Blockchain is the technology that makes trustless digital money possible; everything else in this Academy builds on it.