Blockchain and Web3 are an emerging suite of technologies which can add all sorts of capabilities to embedded products. Blockchains are basically a public ledger / database and everything that happens on them is available to access by any internet-connected device.
There are lots of blockchains in existence, but many of them are not really useful for anything more than speculative investing. The Cardano blockchain however is a true Web3 blockchain with a massive community of developers and enthusiasts. If you’re a newb to all this, there is an onboarding guide to blockchain and Web3 provided by Simple Cardano. They also have a page with many developer links called “Using the Cardano blockchain“.