This research aims to examine students' ability to understand mathematical concepts based on the Skemp Theory. This type of research is a literature study or literature review obtained from the Skemp book. The steps of this research are designing a review, conducting a review, analyzing, and writing a review. The results of the study show that relational understanding can help students solve problems by thinking more broadly, critically, and structured. Meanwhile, students with instrumental understanding solve problems quickly, correctly, and not using procedures.