Accessible Digital Textbooks (ADT) are digital learning resources designed from the outset to be accessible to all learners, including children with visual, hearing, physical, cognitive, or learning disabilities. Unlike traditional digital books, ADTs incorporate accessibility features as an integral part of their design, ensuring that every learner can access, understand, and interact with educational content in an inclusive and meaningful way. Common features include text-to-speech functionality, adjustable font sizes and styles, high-contrast display modes, image descriptions (alt text), keyboard navigation, multilingual support, captions for audio and video content, and interactive learning activities that accommodate diverse learning needs.

Universal Design for Learning (UDL) is an educational framework that guides the development of flexible learning environments and resources that address individual learning differences. UDL recognizes that learners vary in how they engage with information, process content, and demonstrate what they know. By providing multiple means of engagement, representation, and action and expression, UDL helps remove barriers to learning and promotes equal opportunities for success. When combined with Accessible Digital Textbooks, UDL supports a more inclusive education system where every child can learn at their own pace, using tools and formats that best match their abilities, preferences, and needs.