AWS provides a convenient mechanism for assigning IAM roles to EC2 instances, allowing applications running on these instances to inherit the permissions associated with those roles without needing to embed credentials or keys in the code. This approach simplifies and secures deployment practices by enabling the assignment of roles to EC2 instances either during their creation or to existing ones using the AWS CLI. Once assigned, these roles can be utilized to assume secondary roles, offering additional permissions for specific tasks, similar to using the sudo command. The process involves creating trust policies to allow the EC2 service to use these roles and accessing instance metadata to generate keys that can be used by the AWS CLI and other tools, which automatically retrieve and use these credentials without needing manual configuration. This flexible security model enhances the management of permissions and execution of processes with varying privileges, promoting a more secure and dynamic cloud environment.