Crypto is a shortened form of the word "cryptocurrency". Cryptocurrency is a digital or virtual currency that uses cryptography for security and is decentralized, meaning it is not controlled by a central authority (such as a government or bank).

Cryptocurrencies are based on blockchain technology, which allow them to operate without the need for intermediaries like banks and enables secure, transparent, and immutable transactions. Bitcoin is the most well-known cryptocurrency, but there are many others, such as Ethereum, Dogecoin, and Solana, each with their own unique features and uses.

Crypto can also refer more broadly to the ecosystem of technologies, communities, and applications that surround cryptocurrencies and blockchain.