Think of it like a free Uber app where taxi drivers and customers can connect together without having to pay the middleman company a cut of profits.
They are permanently based on the blockchain.
These cryptocurrencies and many others are available to buy and sell on crypto exchanges.
Of course, that's also true of traditional financial systems and currencies.
You can also arrange to trade cryptocurrencies in-person with peer-to-peer sites like.
There are no rules about who can own or use cryptocurrencies.