Cryptocurrency is a type of digital currency that uses cryptography for security and anti-counterfeiting measures. It is basically digital fiat or 'electronic money'. It is computer generated and computer driven. To exchange this digital money, public and private keys are used to transfer cryptocurrency between individuals and/or exchanges.
As cryptocurrency has no 'real' intrinsic value, users must reach a consensus about cryptocurrency's value and use it as an exchange medium. However, because it is not tied to a particular country, its value is not controlled by a central bank, i.e. it is decentralized. Value is solely determined by market supply and demand, meaning that it behaves much like precious metals, like silver and gold. This all takes place electronically and therefore has numerous advantages over regular fiat money in that it can be transferred to anyone, anywhere in the world who has access to the internet.