OpenIntro Statistics, David M Diez, Christopher D Barr, Mine Çetinkaya-Rundel, 2019 (OpenIntro) - A freely available, high-quality textbook covering fundamental statistical concepts, including data types.
Introduction to Probability and Statistics (18.05), Jeremy Orloff, Jonathan Bloom, 2014 (MIT OpenCourseWare) - Offers a structured academic approach to fundamental statistical concepts, including data types and their characteristics.