OPC UA Applications represent software or devices that provide information to other OPC UA Applications or consume information from other OPC UA Applications.
This Annex contrasts the Subscription functionality available in the Client Server communication model with the data distribution mechanism of PubSub. See The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments and errata) applies.
OPC 10000-1 for an overview of the complete functionality available with the Client Server model.