An IT engineer needs to access AWS services from an on-premises application.

IAM access keys are long-term credentials that consist of an access key ID and a secret access key. You use access keys to sign programmatic requests that you make to AWS. If you need to access AWS services from an on-premises application, you can use IAM access keys to authenticate your requests. AWS account user name and password are used to sign in to the AWS Management Console. Amazon EC2 key pairs are used to connect to your EC2 instances using SSH. AWS Key Management Service (AWS KMS) keys are used to encrypt and decrypt your data using the AWS Encryption SDK or the AWS CLI.