In this five-minute preview overview, Xavier Ducuyper, of the YouTube channel “Simply Explained”, gives a brief but clear explanation on what cryptocurrencies are, what a blockchain is, what smart contracts do, what decentralized finance (DeFi) is, and how each of these can be used. Xavier will deliver two presentations at the Catholic/Crypto Conference 2022: An Introduction to Blockchain and An Introduction to DeFi (Decentralized Finance).