A way to look at it: "Blockchains" are just large distributed immutable databases, Bitcoin being the first working proof of concept to be a "public ledger," --

A way to look at it: "Blockchains" are just large distributed immutable databases, Bitcoin being the first working proof of concept to be a "public ledger," -- but pretty much only for "money." Ethereum (really, the ERC-20 ethereum blockchain) is designed to not just be a "money" database, but a "general purpose" database. So you could theoretically build anything on it. One major use is "other coins," but you can do e.g. lotteries, NFTs, other forms of finance, game tokens -- anything where a publicly viewable/auditable database may be of some use. And also, like other programming things, lots of footguns. :)