An Amazon ECS cluster is a logical grouping of tasks or services.
- If you are running tasks or services that use the EC2 launch type, a cluster is also a grouping of container instances.
- If you are using capacity providers, a cluster is also a logical grouping of capacity providers.
- A Cluster can be a combination of Fargate and EC2 launch types.
When you first use Amazon ECS, a default cluster is created for you, but you can create multiple clusters in an account to keep your resources separate.
For more information on ECS Clusters, see here.