Bitcoin is a digital currency and also refers to the open source
software that uses it, and the peer-to-peer network that it
Unlike most currencies, Bitcoin does not rely on trusting any
central issuer. Bitcoin uses a distributed database spread across
nodes of a peer-to-peer network to journal transactions, and uses
cryptography in order to provide basic security functions, such as
ensuring that bitcoins can only be spent by the person who owns
them, and never more than once.
Irreversible transactions of any value can be sent internationally
in moments for next to no significant cost.