Quote from: planaree on July 19, 2017, 01:23:47 PM

So, if I keep only the passphrase, can I get back my wallet
from another client (not Electrum) ?

Or I can deduce the private key from the passphrase ?

I understand that if I keep only my private key, it's enough
to access my coins with any wallet.

1) no, usually you can only use the seed (passphrase) to restore your wallet within electrum. This is because other wallets use different derivation paths.

2) yes, you can deduct the xprv from the seed, and in turn, you can derive all private keys from this xprv.

3) yes, your private keys are sufficient. However, most wallets (including electrum) create new private keys -> public keys -> addresses in order to use as a change address every time you create a transaction. Also, each time you generate a payment request, most wallets will generate a new private key/public key/address combination. If you only export/backup your current private keys, you won't be able to spend BTC that was sent to the new addresses that were generated afterwards.
This is why it makes more sense to save your seed phrase. When restoring your wallet using this seedphrase, electrum will be able to regenerate your xprv, and regenerate ALL funded private keys/public keys/addresses, not only the ones that were in use at the time of the backup Wink