Yes, a Dedicated Instance guarantees physical isolation from other AWS accounts, but can share hardware with other instances in the same account
To manage licenses and control physical server placement.
Capacity Reservations are primarily for ensuring the availability of compute resources, not for cost savings.
Use Capacity Reservations to guarantee instance availability.
Use RIs to get long-term cost savings.
Dedicated Instances: Run on hardware isolated to a single customer, but you don’t have control over the physical server.
Dedicated Hosts: Provide full control over the physical server, useful for license management and compliance.