This document provides an overview of hospital information system architectures and strategies. It begins by defining the types of data processed in hospitals, including patient, resource, administrative, and management data. It then describes the main hospital functions like patient care, supply management, administration, and management. Under patient care, it outlines functions like admission, treatment planning, order entry, care delivery, and discharge. It provides details on what each function involves and what data is used. The document aims to explain the components of a hospital information system and how they can be integrated to support clinical and business operations.