Cryptocurrencies developed from earlier ideas about digital cash, cryptography and distributed networks. Blockchain technology brought those ideas into a system where transactions could be recorded without a single central operator.
From concept to network
Early experiments established the building blocks. Bitcoin’s launch in 2009 showed how a public ledger and a consensus mechanism could work together at scale.
The field has since grown into many networks and applications, with continuing debate about energy use, governance, privacy and practical value.