NK-12 refers to a classification system used in education that encompasses all levels from nursery through 12th grade. This system is designed to provide a structured framework for students' learning experiences, ensuring a continuum of education from early childhood to the end of high school. The NK-12 model emphasizes the importance of foundational skills in early education, which are built upon as students progress through each grade. This approach aims to prepare students for higher education or the workforce by fostering critical thinking, creativity, and social skills throughout their academic journey.