Amazon Relational Database Service (RDS) is a distributed relational database service by Amazon Web Services. It is a web service running in the cloud designed to simplify the setup, operation, and scaling of a relational database for use in applications.
Amazon Web Services (AWS) is a comprehensive, evolving cloud computing platform provided by Amazon that includes a mixture of infrastructure as a service (IaaS), platform as a service (PaaS) and packaged software as a service (SaaS) offerings.
Salesforce Heroku is part of the Salesforce Platform, enabling enterprises to store and leverage customer data in Salesforce for full-cycle CRM engagement.