Sextant keeps track of Kubernetes clusters that it is allowed to use as targets for deployments.
Sextant can work with clusters wherever they are hosted regardless of where
Sextant is itself deployed. For example, you could subscribe to the
Sextant Premium Edition on the AWS Marketplace but target clusters
provisioned on AWS, GCP or Azure.
Finally, while a comprehensive guide on Kubernetes is out of scope if you are working with AWS then EKS Cluster Basics may be useful.