EC2 Instance Savings Plan
A commitment to a specific instance family in one region, for a discount close to a Standard RI but with size flexibility.
An EC2 Instance Savings Plan commits you to a specific instance family (e.g. m7g) in a specific region for 1 or 3 years. Within that family and region you can freely change size, OS, and tenancy and keep the discount.
Because it is narrower than a Compute Savings Plan, the discount is larger — typically matching a Standard Reserved Instance of the same term and payment option. It is a good middle ground: more flexible than an RI, cheaper than a Compute Savings Plan, as long as you know which family you will keep running.