# Systems Manager Features

## Sessions Manager

* Session Manager is a fully managed Systems Manager capability that **lets you manage your EC2 instances, on-premises instances and VMs through an interactive one-click browser-based shell or through the AWS Command Line Interface (AWS CLI)**.\\

* Some benefits:\\

  * **Centralized access control to instances using IAM policies** - Administrators have a single place to grant and revoke access to instances.
  * **No open inbound ports** and **no need to manage bastion hosts or SSH keys**.
  * **One-click access** to instances from the console and CLI.
  * **Port forwarding** - Redirect any port inside your remote instance to a local port on a client.
  * **Cross-platform support** for Windows, Linux, and macOS.
  * **Logging and auditing** session activity using CloudTrail and CloudWatch Logs.

## `Run` Command

* Systems Manager Run Command lets you **remotely and securely manage the configuration of your managed instances**.\\

* It enables you to **automate common administrative tasks** and **perform ad hoc configuration changes at scale**.\\

* For example, it can be used to: **install or bootstrap applications**, **build a deployment pipeline**, **capture log files when an instance is terminated from an Auto Scaling group** and **join instances to a Windows domain**, etc.

## Patch Manager

* Systems Manager Patch Manager **automates the process of patching managed instances** with both security related and other types of updates.\\

* You can **scan instances to see only a report of missing patches (`scan`) or you can scan and automatically install all missing patches (`scan and install`)**.\\

* A **patch baseline defines which patches are approved for installation on your instances** - You can **specify approved or rejected patches one by one**. Also, the **rejected list overrides both the rules and the approve list**.\\

* Systems Manager Maintenance Windows let you **define a schedule for when to perform potentially disruptive actions on your instances such as patching an operating system, updating drivers, or installing software or patches**.

## Parameter Store

* Systems Manager Parameter Store provides **secure, hierarchical storage for configuration data management and secrets management**.\\

* You can **store data such as passwords, database strings, Amazon Machine Image (AMI) IDs, and license codes as parameter values**.\\

* You can **store values as plain text or encrypted data**.\\

* You can **reference Systems Manager parameters in your scripts**, commands, SSM documents, and configuration and automation workflows **by using the unique name that you specified when you created the parameter**.
