Containers are a solution to the problem of how to get software to run reliably when moved from one computing environment to another. This could be from a developer’s laptop to a test environment, from a staging environment into production, and perhaps from a physical machine in a data center to a virtual machine in a private or public cloud.
AWS Beanstalk deploy and manage application on AWS Cloud without worrying about the environment to run your web application. No need to create and manage EC2 instance for a single application.
AWS OpsWorks is an application management service or tools that makes it easy for the DevOps user to model & manage their application. It is a tool on AWS Cloud similar to Chef, Puppet which can manage a number of servers.
AWS Cloud Formation helps developers and system administrators by providing easiest way to create and manage a large number of AWS resources, provisioning and updating them in an orderly and predictable fashion. By using cloud Formation in few hours you can build up your large scale environment from a single template.