It is a digital form of money that is encrypted (and therefore secured) by cryptography. Bitcoin is the first cryptocurrency that is decentralised and runs on a blockchain.
Today, there are thousands of other cryptocurrencies built on a decentralised and secured network. All of them, besides Bitcoin, are called alternative coins or “altcoin”. Cryptocurrencies are industry agnostic, meaning they are not specific to a market or sector but can impact our economy and our society as a whole.