I have a question if we lost back up seed words or key is there any other way to ricover our account?
(Edit: If you don't keep the persistent storage with your wallet) those "random words" are
the only thing that allows anybody to spend coins from your "addresses".
This means:
1. you have to keep them super-safe (and that means NOT on the internet)
2. you can always recover your wallet with Electrum and those words
3. if somebody else gets them he will steal your coins
4. if you lose those words those coins are lost (locked there) forever; you can "see" them but never again spend them (OK, there are other ways to backup the wallet so you can still spend, but let's keep it simple).
Edit: Please read the previous post, it better the things needed for accessing a wallet (any one of the 3 does the job)
This post was/is an attempt to explain it clearer.