Instance Metadata Service (IMDS) allows an instance to access information about itself, such as its instance ID, IAM roles, security group settings, and other relevant metadata, without needing to use credentials. It’s a way for applications running on the instance to retrieve configuration information or credentials dynamically, making it easier to work with cloud resources securely.

Version 2 (IMDSv2) is an enhanced and more secure version of the service that AWS introduced to address potential security vulnerabilities. IMDSv2 introduces additional security measures to prevent certain types of attacks that could exploit the service.