Creating a storage factory smart contract in Solidity and interacting with it (notes from Freecodecamp)

I'm following Freecodecamp's wonderful web3 course on Youtube (link here => https://www.youtube.com/watch?v=gyMwXuJrbJQ&ab_channel=freeCodeCamp.org), and to make sure that I remember what I've learnt, I like to take notes. Here, I'll post my notes fr...