Quote from: alexlouismorlevat on November 08, 2017, 01:19:48 AM

I read the best way is to store them on a USB key, or even better, on a specific device called the Ledger Nano S (less expensive option it seems?).
I don't understand exactly how does BTC works with this device?
Are the BTC transferred INTO the device?

Basically, it will create wallet address and private. So your btc will transfered to hardware wallet adress. More info how it works https://bitfalls.com/2017/09/08/hardware-wallets-like-ledger-nano-s-work/

Quote from: alexlouismorlevat on November 08, 2017, 01:19:48 AM

Hello,
I read that if you lose the device, you can still access your BTC, so: what's the point of having this device? And would that mean that the BTC are not actually stored on the device? since losing it doesn't mean that you lose access to the BTC. So my previous statement above is wrong?

You can access it if you have something called "Backup". Example is Private Key and Seed. So even your hardware wallet is lost, you can still access it if you backup it before. Like save your private key and seed or print it.

Quote from: alexlouismorlevat on November 08, 2017, 01:19:48 AM

And it's said to use your device instead of an online service wallet like bitgo or greenéddress? greenbits?? or whatever??
But on the device sales page it says that we can use the device with those online services.

It mean you can use them for do transaction like send to another address and etc.