Bank transfers have different names in different countries. It can be called a wire transfer, ACH and many other names. The process usually involves receiving casino bank details that can be used by players. They then use these details to make a payment to the online casino through their online banking.
The same can be said for making a withdrawal. Bank transfer is simple and is overseen by financial institutions so it is also safe. Privacy is also an important part of making a bank transfer. There is no need to sign up online for e-wallets and other payment methods which use the client's personal data.