Software Engineering Institute

Department of Defense documentation describing cyberspace-related concepts uses a variety of terminology defined in joint doctrine—but also other sometimes ambiguous terms in documents, presentations, and references—often implying a similar meaning to official terminology, yet without clear definitions. Clear definitions avoid confusion and misunderstanding based on metaphor, simile, or implied meaning that may be interpreted differently by readers with different perspectives on cyber operations (CO) or mission planners working at different tactical, operational, and strategic levels who need to include the intended and unintended effects of CO in their mission analysis and planning. It is important for commanders and the technical experts on their staff to have a shared understanding of key terms in order to integrate CO into multidimensional mission analysis and mission planning. This paper discusses the relationships between several terms used to describe characteristics of CO and how they relate to other terms important to military operations and mission planning. Focusing on defensive cyber operations, we discuss key terrain-cyber and mission-relevant terrain-cyber and review current definitions for each term and their synonyms. We also describe how these terms relate to the joint doctrine multi-domain concept of key terrain.