What is user interface integration?
USD borrows a lot from User Interface Integration (UII) and should ultimately make configuration of customized agent application not only easier but also faster. Basically, UII makes it possible to build and use composite agent applications for unified access to customer information stored in Microsoft Dynamics CRM and other external systems.
USD lives inside of Dynamics CRM and consists of a set of solutions files containing entities and configuration data relevant to the UII framework. Once installed, you configure your application by defining Hosted Controls (Pages), Toolbars, Events, Navigation Rules, Actions and so on. The USD configuration section of CRM is shown below:

Note that you do not need much coding so the lead time to designing agent applications is significantly reduced. Additionally, the technology uses a computer telephony integration (CTI) framework that enables businesses to integrate Unified Service Desk with existing IT telephony infrastructure for greater customer desk convenience.