This paper discusses the importance of context in interactive applications, particularly in handheld and ubiquitous computing where user context changes rapidly. The authors aim to better understand context and context-aware applications to improve the development of context-aware systems. They review existing research on context-aware computing and provide definitions and categories of context and context-awareness. They conclude with recommendations for a framework to support context-aware application development. Context is defined as any information that can be used to characterize the situation of an entity, such as a person, place, or object. The primary context types are location, identity, time, and activity. Context-aware applications use this information to provide relevant information and/or services to users. The authors also categorize context-aware applications into three main features: presentation of information and services, automatic execution of services, and tagging information with context. The authors also discuss the differences between previous definitions of context-aware computing and propose a more general definition that includes applications that simply display context without modifying behavior. They present a categorization of context-aware features, which includes contextual sensing, adaptation, resource discovery, and augmentation. These features help application designers understand the boundaries of context-aware computing and select appropriate context for their applications. The authors also describe an architecture for supporting context-aware computing, which includes context widgets and context servers. Context widgets collect context information, while context servers manage the context about a single entity. The architecture supports the development of context-aware applications by providing a framework for context sensing, processing, and utilization. The paper concludes that a better understanding of context and context-aware computing is essential for developing effective context-aware applications. The authors have begun work on a framework to support the development of such applications, which is influenced by the definitions and categorizations presented in this paper. Through the use of this framework and the development of more applications, the authors hope to further increase their understanding of context and context-awareness.This paper discusses the importance of context in interactive applications, particularly in handheld and ubiquitous computing where user context changes rapidly. The authors aim to better understand context and context-aware applications to improve the development of context-aware systems. They review existing research on context-aware computing and provide definitions and categories of context and context-awareness. They conclude with recommendations for a framework to support context-aware application development. Context is defined as any information that can be used to characterize the situation of an entity, such as a person, place, or object. The primary context types are location, identity, time, and activity. Context-aware applications use this information to provide relevant information and/or services to users. The authors also categorize context-aware applications into three main features: presentation of information and services, automatic execution of services, and tagging information with context. The authors also discuss the differences between previous definitions of context-aware computing and propose a more general definition that includes applications that simply display context without modifying behavior. They present a categorization of context-aware features, which includes contextual sensing, adaptation, resource discovery, and augmentation. These features help application designers understand the boundaries of context-aware computing and select appropriate context for their applications. The authors also describe an architecture for supporting context-aware computing, which includes context widgets and context servers. Context widgets collect context information, while context servers manage the context about a single entity. The architecture supports the development of context-aware applications by providing a framework for context sensing, processing, and utilization. The paper concludes that a better understanding of context and context-aware computing is essential for developing effective context-aware applications. The authors have begun work on a framework to support the development of such applications, which is influenced by the definitions and categorizations presented in this paper. Through the use of this framework and the development of more applications, the authors hope to further increase their understanding of context and context-awareness.