I tell people a website is like a payment terminal. Your device is like your debit card. A password is like a PIN on the card. A Passkey is like a chip on the card.
Logging into a site with your device is like putting your card into the terminal. The site can ask for a password the way the terminal asks for a PIN, but if your device supports Passkeys, that’s like your card having a chip, and it’ll use that instead.
So think of Passkeys like using a chip card.
I dunno how well this analogy works down to the last detail but it has gotten it across to all the parents I’ve used it with
Do most people understand why cards have a chip in them now?
Probably not. The magnetic strip was easy to explain (it contains some info the terminal checks, it's functionally just a long password), but it's also pretty easy to explain why skimming was a problem. Explaining how chips fixed that (signing keys and cryptography) is probably beyond a 30 second explanation with Joe Schmo.
Then again, I doubt most people care to know, which is why that explanation works. They're not going to ask 'where is the passkey in my computer?'.
Great analogy, am going to use that going forward, thank you.