You will be given a few options, most companies will want to pay you on a Visa/Mastercard debit card that you can use inside the ship (ATM machine for crew, with no fees charged) or outside of the ship. This card also works for online shopping in stores such as e-Bay, Amazon and similar.
If you are American or Canadian, most companies will be able to do wire-transfer to your own bank account. Please ask HR on your sign-on date.
Some crewmembers use Western Union or similar services to send their salary home to a family member, friend, or bank. It is the most innovative and safest option.
Or you can keep your salary in your “Ocean Pay” and withdraw before going home.