With crypto, the only component you need to worry about having physical possession of is your backup seed phrase. It's a combination of 12-18 random words that will be used to generate your private keys and unlock full access to your entire wallet.

People sometimes use pen and paper to write the words down, but that can get lost or destroyed easily, so there are lots of creative ways people have come up with to create secure offline backups.

Suppose your house burns down and your electronic devices are all destroyed. A paper wallet wouldn't survive and you'd lose everything, but if you had a fireproof backup like this, you could restore your wallet on a new device.

The dark side to this is that if anyone else gains access to your backup phrase, everything in that wallet is gone. Most crypto "hacks" are just because people are careless when they save their seed phrase, like taking a screenshot and saving it in the cloud.