Oracle SOA Suite is a set of products from Oracle which cover the Middleware aspect of an organization. It includes an ESB, BPEL Engine, Workflow, B2B, Business Rules, to mention but a few features.

Middleware is the Technology Infrastructure that connects different systems together in a coherent and standardized manner.

SOA stands for Service Orientated Architecture. It is a Enterprise Level Strategy based on leveraging existing systems and combining that with Architectural Best Practices, Business Objectives, Technology Architecture and People.