The pattern is that utility services are prefixed with AWS, while standalone services are prefixed by "Amazon".
Services prefixed with AWS typically use other services, for example:
- AWS Elastic Beanstalk, AWS OpsWorks and AWS CloudFormation launch other services
- AWS Lambda is triggered by other services
- AWS Data Pipeline moves data between other services
- AWS CloudFormation launches other services
Mind you, this doesn't apply to everything. For example, Amazon EBS can only be used with Amazon EC2, yet it has an "Amazon" prefix.
The AWS documentation page is a great reference for determining the official name of a service.
naming conventions - Why some services are called "AWS XXX" and the others "Amazon XXX" - Stack Overflow
