Skrill is a digital wallet. You register, verify your account, and then pay websites using your email address and password, so the casino does not see your financial details. You can hold a balance in the wallet, or fund payments from a bank account or card.
That last point matters in the UK. The Gambling Commission says licensed operators should check that money in an e-wallet was not loaded from a credit card, and can only accept e-wallet payments where the wallet prevents credit card use for gambling. Fund your wallet from a bank account or debit card.
Where a casino pays withdrawals to Skrill, you then move the money from the wallet to your bank. Each step can carry its own fee and timing, set by the casino and by Skrill, so check both price lists before you rely on it.
Skrill accounts need verifying before you can move money, and the casino will run its own age and identity checks too. Use the same name and address on both to avoid delays when you withdraw.
Source: www.skrill.com