Eth staking with Ledger

Apparently Ledger just added ethereum staking. Just read an article about it but I’m not clear on some things. The article I read says they use Lido for the staking service and there’s a 10% fee. I don’t exactly understand when the fee comes in to play. Does it mean when you complete the staking process they charge 10% and 10% of what? Sorry if it’s a stupid question. I’m still relatively new and haven’t staked before. It also wasn’t clear to me what the percentage payout is. It did say you’re paid with stETH which I’m not familiar with. Thanks for any insight and help with me understanding this better.