Why use an additional passphrase on your Trezor?

Do you have a Trezor hardware wallet? I have one, but I haven't really been using it. In addition, I have often messed up and felt confused about the difference between the recovery keys (12, 18 or 24 words) and between the passphrase. What is the difference?

Recently, I recovered a wallet with the recovery keys, and then I suddenly saw that I could add a passphrase as well afterward. What is it about?

Hidden wallets within your wallet!

Let us say that you have a recovery key consisting of 18 words. You have quite a lot of funds on it, and everything is nice. But, then someone actually finds the recovery keys that you have hidden in your bedroom, which means, they now have access and the possibility of stealing all the funds that you have stored and connected to this wallet.

But, that is when the passphrase turns interesting. The passphrase can be your 19th hidden word. What do I mean? If someone gets ahold of your recovery keys, then they will get access to your wallet and see the transactions with your wallet. But, you can also add an additional passphrase, and without it, all the thief/hacker will see, is your normal wallet, and not your hidden wallet which is protected by an additional passphrase. Do you see what I mean?

Let us say that someone forces you to reveal your recovery keys. If you have some funds in that wallet, they might say thank you, and steal it. At the same time, you know that the real values are hidden within your hidden wallet, protected by the additional passphrase. And by the way, you can run with several passphrases using the same hardware wallet.

You can create a passphrase with the code word: IL0veHiVe and it will open one wallet. You can also access another hidden wallet with the passphrase 1L0vEhIvE. In other words, each type difference will give you access to another wallet. But be careful, if you forget your passphrase, you will never ever get access to that wallet again. That is kind of scary as well!