The connectivity is a component that provides access to a data source of some kind. It can (and usually does) support reading, writing, subscriptions, and browsing.

Three connectivity components are currently provided with QuickOPC: The DAConnectivity (for OPC Data Access and OPC XML-DA), the UAConnectivity (for OPC Unified Architecture), and the CompositeConnectivity (can be configured to contain and combine any number of other different connectivity components).