This article provides a comprehensive overview of food and nutrition security definitions, constructs, frameworks, measurements, and applications, drawing on global experiences. It emphasizes the importance of food security (FS) as a key social determinant of health (SDOH) and its role in achieving the Sustainable Development Goals (SDGs). The article clarifies the definitions of FS and nutrition security, outlines the links between the two constructs, summarizes measurement approaches, and illustrates their applications in monitoring, policy design, and research. It highlights the development and global dissemination of experience-based food insecurity (FI) scales, such as the US Household Food Security Survey Module (USHFSSM), which have been instrumental in advancing FI research, policy, and program evaluation. These scales have been adapted and validated globally, including in Latin America, and have informed the development of the Food Insecurity Experience Scale (FIES) used to track SDG 2.1.2. The article also discusses the integration of water insecurity measures, such as the Household Water Insecurity Experience Scale (HWISE), to address the complex interplay between water and food security. It underscores the importance of using experience-based measures to improve FS governance and policy design, and highlights the need for systematic sharing of lessons learned across countries to enhance global efforts in addressing food and nutrition security. The article concludes by emphasizing the importance of clear, concise definitions and frameworks for FS and nutrition security, and the role of international collaboration in advancing these efforts.This article provides a comprehensive overview of food and nutrition security definitions, constructs, frameworks, measurements, and applications, drawing on global experiences. It emphasizes the importance of food security (FS) as a key social determinant of health (SDOH) and its role in achieving the Sustainable Development Goals (SDGs). The article clarifies the definitions of FS and nutrition security, outlines the links between the two constructs, summarizes measurement approaches, and illustrates their applications in monitoring, policy design, and research. It highlights the development and global dissemination of experience-based food insecurity (FI) scales, such as the US Household Food Security Survey Module (USHFSSM), which have been instrumental in advancing FI research, policy, and program evaluation. These scales have been adapted and validated globally, including in Latin America, and have informed the development of the Food Insecurity Experience Scale (FIES) used to track SDG 2.1.2. The article also discusses the integration of water insecurity measures, such as the Household Water Insecurity Experience Scale (HWISE), to address the complex interplay between water and food security. It underscores the importance of using experience-based measures to improve FS governance and policy design, and highlights the need for systematic sharing of lessons learned across countries to enhance global efforts in addressing food and nutrition security. The article concludes by emphasizing the importance of clear, concise definitions and frameworks for FS and nutrition security, and the role of international collaboration in advancing these efforts.