So my son is dabbling. I explained the concept of a hardware wallet...and the importance of securing seed words.
He asked a question I couldn't answer (googling included).
How does your wallet 'know' that your seed words represent all your tokens? Let's say you set up a brand new hardware wallet and generate your seed words. A couple of days later you buy n number of tokens on different chains.
How do the seed words represent all that? He's concerned (bless him) that they must be stored on a database somewhere.
I couldn't give a straight answer...other than my reddit knowledge tells me so.