AWS Elastic Container Registry & Elastic Container Service

ECR

Fully mananged container registry.
Scalable.
Management capabilities like automate deleting images based on specified rules and replicating images to other accounts or AWS Regions.
Integrated with ECS (Elastic Container Service) & ECK (Elastic Kubernetes Service).

ECS

Fully managed container service.
Good for deploying, running, and managing containerized applications.
Automated deployment platform.
Run tasks with constraints on CPU, Memory etc.
Think Nomad but deeply tied in with the AWS services and ecosystem.