Digital inequalities in education have been largely studied through the lens of technology access and usage. Although, they are recognized as a multidimensional phenomenon, there is a need for a comprehensive typology that provides useful explanations of their nature. In this paper, we propose a taxonomy of digital inequalities in the French education system, that defines their multiple dimensions, what they cover and who they affect. It defines seven dimensions including technological skills and usage, social, economic, geographical, and public policy factors, affecting students, teachers, and schools. It is based on existing literature and provides a framework for analyzing diverse educational data that will help to predict useful indicators of digital inequalities in education. This work will help to evaluate the impact of a public policy program in the French education system.