tenancy

The tenancy of the instance. An instance with a tenancy of dedicated runs on single-tenant hardware. An instance with a tenancy of host runs on a Dedicated Host.

If tenancy is set to host, then you can optionally specify one target for placement – either host ID or host resource group ARN. If automatic placement is enabled for your host, and you don't specify any placement target, Amazon EC2 will try to find an available host for your build and test instances.