A bare metal is a physical computer server that is offered for rental in a distinct physical piece of hardware that is a functional server on its own (not like VM which running in multiple pieces of shared hardware). It is used by one consumer, or tenant, only.
Bare Metals are charged on monthly, 3 months, 6 months, or annually basis according to your choice in the create page. After creating one (or more) Bare Metal, your credit will be immediately deducted and an invoice will be issued. The invoice item includes the bare metal(s) you create and the additional public IP address(es) if any. In the next period you will be charged again if you are still using it.