Windows Server version and License
Windows Server version
An Amazon EKS Optimized Windows AMI is based on Windows Server 2019 and 2022 Datacenter edition on the Long-Term Servicing Channel (LTSC). The Datacenter version doesn’t have a limitation on the number of containers running on a worker node. For more information: https://docs.microsoft.com/en-us/virtualization/windowscontainers/about/faq
Long-Term Servicing Channel (LTSC)
Formerly called the "Long-Term Servicing Branch", this is the release model you are already familiar with, where a new major version of Windows Server is released every 2-3 years. Users are entitled to 5 years of mainstream support and 5 years of extended support.
Licensing
When launching an Amazon EC2 instance with a Windows Server-based AMI, Amazon covers licensing costs and license compliance for you.