This document provides an overview of health information systems (HIS). It defines HIS as a set of components and procedures that generate information to support health care management decisions at all levels. Effective HIS is important for evidence-based decision making. However, current systems often have imbalances between data supply and demand. The document outlines various users and types of health information needed, and components of effective HIS like disease surveillance and vital records. It also discusses challenges faced by old HIS in Ethiopia and improvements in the new design, like standardization, integration, and simplification to reduce data burden.