Learning key nutritional assessment terminology is critical for ensuring individuals’ health outcomes are being met and enabling clear communication between the health care team. This chapter will explore and define several terms that will be utilized in this text as well as in the professional realm and research. Several of the definitions will use current key global agencies’ categories as they share common frameworks for describing malnutrition, anthropometric indicators, and specific population-level indicators. Successful navigation and understanding of this terminology will equip readers with the language and tools necessary to interpret data accurately, apply evidence-based practices, and contribute effectively to both patient care and broader public health initiatives.