I installed Electrum and created a wallet there. All I know is the seed generated. I don't know private keys from the Bitcoin addresses it manages for me. And I don't see an option to get them from there. So, the question is how safe this system is? Won't I lose my bitcoins one day?
It is one of the safe wallet but not 100% because electrum faced vulnerability on it couple of time as far as I remember and many lost their funds due to it.
The best way to avoid this is keep your electrum upto date.