Crypto or more specifically Cryptocurrency is made up of two words, crypto and currency.  It is digital money and the first part of the name is derived from cryptography which is a security aspect of computer science which made the technology of digital currency possible.  The second part currency deals with the flow of energy, in this case monetary energy.  There are various cryptocurrencies with BTC (Bitcoin) and ETH (Ethereum) being the most popular along with some “alternative coins” referred to as Alt-Coins emerging every day.