AWS Instance tenancy refers to how an Amazon Elastic Compute Cloud (EC2) instance is placed on the underlying physical host, and whether it is dedicated solely to the customer or shared with other customers.
Reserved instances are a way to save money on AWS EC2 instances by committing to a certain usage level over a one- or three-year term.
With reserved instances, customers can choose between three tenancy options:
Dedicated Instance: A physical server that is dedicated to a single customer.
Dedicated Host: An entire physical server that is dedicated to a single customer.
Default tenancy: An EC2 instance that is shared with other customers on the same physical host.
Spot instances, on the other hand, are a way to purchase spare computing capacity at a discounted rate.
With spot instances, customers bid on unused EC2 capacity, and if their bid is above the current market price, they can use that capacity until the spot price exceeds their bid or they terminate the instance.
Spot instances are always launched as default tenancy, which means they can share the same physical host with other customers' instances.
In summary, the tenancy options for AWS EC2 reserved instances include Dedicated Instance, Dedicated Host, and Default tenancy, while spot instances are always launched as Default tenancy.
