SSM stands for "Systems Manager" and refers to a collection of capabilities provided by Amazon Web Services (AWS) to help manage applications and infrastructure running in the AWS Cloud. The AWS Systems Manager Agent (SSM Agent) is Amazon software that runs on Amazon Elastic Compute Cloud (Amazon EC2) instances, edge devices, on-premises servers, and virtual machines (VMs) to enable Systems Manager to update, manage, and configure these resources. SSM Agent processes requests from the Systems Manager service in the AWS Cloud and sends status and execution information back to the Systems Manager service using the Amazon Message Delivery Service. SSM documents define the actions that Systems Manager performs, including Command documents used by State Manager and Run Command, and Automation runbooks used by Systems Manager Automation.