Pull up a chair and ask @DarthCoin

Your "prove" the ownership of your bitcoins with the 12 or 24 words seed. These words create a public and private key. That is the magic trick and is all you need. And NOBODY else should see those words, only you. You can always check any BTC address into a Bitcoin Blockchain Explorer, like https://mempool.space or https://blockstream.info

Now, you can save those words into:

Please start reading:

and many more on my substack (see the right side list of resources links) and also here:

Anybody, who has some access to the internet can get some BTC, which can be kept in a very large variety of ways: software (hot) wallets or programs, hardware (cold) wallets, paper wallets, or even "brain wallets" if you simply memorize your seed words) that it doesn't requiere to own anything special.

It's up to you, and depending on the amount you own, to chose how to keep it. How do you keep your fiat? A small amount in your pocket for your daily expenses, a larger amount at home, for the week or the month, and even larger amount in a checking account, and your life saving hidden away on a savings account (provided you have access to the banking system), or hidden under your mattress, or invested in property or precious metals or art, etc.

Since the way to prove ownership of BTC is by signing transactions with your private keys, you keep those in wallets depending on the amount. You might keep a small amount in a software wallet in your mobile phone (for your daily expenses), a little larger amount on another software wallet that you don't carry around (a second phone that you keep at home, for example), and your savings on a hardware wallet that you store on your safe.

In any case, you need to back up your wallets, regardless of their type, since there is no third party involved keeping your money. If there is, like an exchange or any kind of custodial wallet, consider it not to be your money (not your private keys, not your money). For making those backups you can use any one (or a combination) of all these "multi-gadgets" being advertised on the internet, from a piece of paper to the most robust device made of the most resistant materials or the most sophisticated piece of equipment, again depending on the amount of money you keep and the level of security you feel confortable to keep it at.

As a rule of thumb, the more BTC you keep, the more you should/might want to invest in keeping it safe. Kind of common sense idea, isn't it? 😅

owning sats comes down to being able to spend them. by whatever means you can accomplish that task.

ultimately it's all about knowing (or having access to) the private key.