The J2EE Connector architecture is used by J2EE tools vendors and system integrators to create resource adapters that support access to application enterprise information systems that can be plugged into any J2EE product.
A resource adapter is a software component that allows J2EE application components to access and interact with the underlying resource manager. Because a resource adapter is specific to its resource manager, there is typically a different resource adapter for each type of database or enterprise information system.
A connector is a J2EE standard extension mechanism for containers to provide connectivity to enterprise information systems (EISs).
A connector is specific to an EIS and consists of a resource adapter and application development tools. A resource adapter is a system-level software driver that is used by an EJB container or an application client to connect to an EIS. Connectors comply with the J2EE Connector architecture (JCA).