Instances

Instances in AWS are virtual servers that run in the cloud.
You can launch instances from Amazon Machine Images (AMIs) that are pre-configured with software and settings.
You can also create your own AMIs and launch instances from them.
You can launch instances in multiple Availability Zones, which are distinct locations that are engineered to be isolated from failures in other Availability Zones.
You can use Auto Scaling to launch or terminate instances automatically based on user-defined policies, schedules, and health checks.
You can use AWS CloudFormation to create and manage a collection of related AWS resources, provisioning and updating them in an orderly and predictable fashion.

User data

You can specify user data when you launch an instance.
User data is a script that runs when the instance starts.
You can use user data to install packages, configure services, and perform other instance customization tasks.

Instance ID: A unique identifier for the instance.
Instance Type: The type of instance, which determines the amount of CPU, memory, storage, and networking capacity.
Public IP Address: The public IP address assigned to the instance.
Private IP Address: The private IP address assigned to the instance.
State: The current state of the instance (e.g., running, stopped, terminated).
Key Pair: The key pair used to connect to the instance.
Security Groups: The security groups associated with the instance.

AWS performs status checks on your instances to ensure they are operating properly.
There are two types of status checks: system status checks and instance status checks.
System status checks monitor the AWS infrastructure, while instance status checks monitor the software and network configuration of the instance.
You can view the status checks for your instances in the AWS Management Console.