Passphrase is a random combination of 12 words with spaces in between, generated from a list of 2048 words. For example: "fatigue idea aim barrel input such stock client dove language base whisper". Coin Wallet also supports 12, 15, 18, 21, 24 word passphrases from other wallets.
Your passphrase is the human readable form of your master private key. Make sure that you save it securely somewhere. Your passphrase is all you need to access/restore your wallet (yes, even if you forget your PIN). If you misplace your passphrase, you also lose your wallet and all the funds in it. Do not show your passphrase to anybody, because if they have your passphrase, they can spend your money.
Coin Wallet does not hold your keys on server in database. We cannot access accounts, recover keys, reset passphrase, nor reverse transactions. Protect your keys & always check that you are on correct URL. You are responsible for your security.