When you first go to gamble online you will want to explore options on how to fund your casino account. Normally people will use a credit card but some cards will not allow direct funds to online casinos and for those card holders they need to explore other methods such as Citadel. These methods are known as web wallets which you first fund them either by credit card or direct bank deposits by wiring or EFT funding.
This will take a bit of time to get started, such as a week but once all is in place it is simple to use and a secure method for funding. Not that you have to worry about the online casinos but many users have spyware on there computers so keeping your risk lower by only using methods that you fund with a certain amount keeps the rest of your money safe just in case. Particularly if you are playing on a mobile device which has been hit hard with spyware and Trojans lately. Some of this is done by being included in apps and others are done with hidden downloads off websites. Just take notice if your phone dies quickly or runs real hot as you may be infected. In any case playing using web wallets is the best option for users.