UDL originated from universal design in architecture which aimed to make buildings accessible to all. This concept transferred to education to make learning accessible to diverse learners. CAST developed UDL to provide multiple means of representation, engagement, and action/expression through flexible instruction. While technology is not required for UDL, it can enhance learning when used to provide varied representations, engagement options, and assessments through tools like videos, interactive programs, and individualized feedback. UDL addresses the varied needs of learners as revealed by brain research on recognition, strategic, and affective learning networks.