Bitcoin is presented as the first cryptocurrency. It is a decentralized digital currency with a fixed supply of 21 million coins, a peer-to-peer network, Proof of Work security, and transparent but pseudonymous transactions.
The important beginner idea is not only that Bitcoin is digital money. It is that Bitcoin showed how a network could record value transfers without relying on a single company, government, or bank to update the ledger.
Source:: Bitcoin and Blockchain Basics