The National Center for Education Statistics (NCES) is launching a new series of Technical Briefs on various aspects of the protection of personally identifiable information in students' education records. While driven by recent events, the principles and practices that are outlined in this series can be applied more generally to personally identifiable information about students. This series of Technical Briefs is intended to be useful for anyone responsible for the development, maintenance, protection, or use of student record data. This first brief discusses basic concepts and definitions that establish a common set of terms related to the protection of personally identifiable information, especially in education records.