Amazon Elastic Container Service (ECS) is a highly scalable, high-performance container orchestration service that supports Docker containers and allows you to easily run and scale containerized applications on AWS. A couple of introductory pages:
Getting started with Amazon Elastic Container Service on AWS
Deploy Docker Containers on Amazon Elastic Container Service (Amazon ECS)
Amazon ECS-optimized Amazon Linux 2 AMI - costs money:
Register Amazon ECS Container Instances with Clusters in Private Subnets on AWS
How to register EC2 Instance to ECS cluster? on Stack Overflow
run-task - detailed description
describe-tasks - detailed description