One tenant, one machine
What arrives when you rent bare metal is a particular computer in a particular rack: a named processor, a fixed quantity of error-correcting memory, disks you selected, a network port, and out-of-band management through IPMI or a vendor console so you can reinstall the operating system or watch it start up without anybody walking over to it. No hypervisor takes its cut, and no neighbour's overnight backup job turns into your slow query. That pitch still holds for a narrow set of workloads. Databases care about consistent disk latency far more than about good average latency. Commercial software licensed per physical core can cost more on a virtualised host than the hardware underneath it does. Regulated environments sometimes need single tenancy written down rather than argued about. And the arithmetic favours a whole machine for anything busy all day, because you pay for the full box either way and a box running near capacity is cheap per unit of work done. What you surrender is everything the cloud normalised. Capacity appears when the provider racks it, not while you wait on the phone. Growing means ordering a second machine and building the coordination between the pair yourself. And hardware breaks: when a disk dies you suddenly care a great deal whether you configured redundancy, whether a spare is already in the chassis, and how fast somebody on site will swap it, because a virtual machine can be rebuilt elsewhere in minutes while a physical one has to be repaired where it stands. Providers have blurred the boundary with bare-metal products that provision real machines through an API and bill by the hour, but the underlying trade has not moved an inch.
Ask these before you order
Both answers live in the provider's own documentation and neither is on the specification sheet. First, what happens when a disk fails: who notices it, who replaces it, inside what window, and whether the replacement is billed. Second, how you reach the machine when it will not boot, which is what remote console access is for and why a plan lacking one is a plan to open a ticket and wait. Single tenancy removes the noisy neighbour, but it also removes the platform that used to migrate your workload off dying hardware while you slept. On your own iron that work belongs to you, and it is made of disk redundancy, restored-and-verified backups, and monitoring loud enough to wake somebody.