As a security requirement, physical servers should not be shared with other companies. Furthermore, even if they belong to the same AWS root account, IAM accounts from different departments should not be able to share physical servers with each other.
- Dedicated Host
What is Dedicated Host?
Dedicated Host is an instance type that physically occupies a server.
Dedicated Hosts allows users to utilize existing licenses on a per-socket, per-core, or per-VM software basis, subject to license terms.
Even if an IAM user or IAM group belongs to the same AWS account, it will not share a physical server with another IAM user or IAM group with different privileges.
Hardware Proprietary Instance
Hardware proprietary instances are physically isolated from instances belonging to other AWS accounts at the host HW level, but may share HW with instances of the same AWS account.
Bare metal is an instance where the application has direct access to the processor and memory of the underlying server.
It can be linked to various AWS services, allowing the OS to directly access lower-layer hardware.