IaaS is a cloud computing model in which storage, compute, and networking resources are available on demand over the internet through an IaaS provider.
BMaaS can be considered a subset of IaaS that refers specifically to the practice of providing access to dedicated servers free of any installed operating systems or virtualisation infrastructure—bare metal. The customer may be provided access to the physical server hardware either remotely or on-premises.
Compared to the traditional cloud model, where multiple users (multi-tenancy) may reside on the same physical server within a cloud vendor’s data centre, the bare metal server only has one customer on the server (a single-tenant server).
Access is usually provisioned on-demand via a single contract or service level agreement (SLA).