A Bitcoin Wallet’s Seed is not its Passphrase.
Bitcoin Wallets have not-so-magical convenient and powerful property: you can rematerialize them out of thin air if you delete one (intentionally or not).
Because of BIP 39 and BIP 44, all ya gotta do is get (from the wallet app) either a twelve-word or twenty-four-word. That is the wallet’s seed. Before storing too much money in that wallet, be sure to get your seed, write it down, delete your wallet, and restore it. Are your transactions still there? Good. Here is where the trouble might come: did you also use a passphrase?
Adding a passphrase to your wallet can make it more secure. Now, in addition to the seed words, you’ve got all the words for the passphrase. Mistaking one for another, or combining them, will make you lose your wallet and, therefore, all of your money.
If you use a passphrase, be sure to:
- Please write it down with extra special loud and memorable notices about how it is a passphrase, not a seed.
- Test out the deletion of your current wallet and restoration using the seed and your passphrase.
It might sound like common sense, but it is easy to forget in the enthusiasm to start with crypto.