Amazon ECS vs EKS

networking

EKS allows up to 750 Pods per instance whereas ECS accommodates only up to a maximum of 120 tasks per instance, this is one of the important points to understand when considering the difference between Amazon ECS vs EKS.

Namespaces

Kubernetes has the concept of namespaces which isolates workloads running in the same cluster, whereas ECS does not have such a concept in it.

Ease of Use

ECS is very straightforward and does not have a lot of components to learn whereas EKS is more complex as it uses Kubernetes which is altogether a vast technology to learn and requires expertise for deployments. ECS does not have any control plane, unlike EKS.

Pricing and Costs

The pricing of ECS and EKS also depends on the infrastructure (AWS Fargate or Amazon EC2) being used to host containerized applications. On top of this, one needs to pay $0.10 per hour for each Amazon EKS cluster for its control plane.

Portability and Compatibility

Both, EKS and ECS, are managed services of AWS. ECS is an AWS proprietary service whereas EKS is a Kubernetes-as-a-platform service by AWS.

Community support

For any software, platform, or framework, community support is essential. Since Kubernetes is an open-source technology. 

https://aws.amazon.com/blogs/containers/amazon-ecs-vs-amazon-eks-making-sense-of-aws-container-services/