The override field is used to specify alternative configurations for EC2 instances in node groups (both managed and self-managed).

example of given override value:

override = {
  instance_type = ["t3a.large", "t3.large"]
}

This field is particularly useful in the following cases:

• When using Spot Instances, to improve availability by providing multiple instance types.
• When configuring mixed instance groups, allowing AWS to choose instances based on capacity and pricing.