Understanding by Design (UbD) is a framework for curriculum development created by Jay McTighe and Grant Wiggins that uses backward design. It consists of 3 steps: 1) identifying desired results, 2) determining acceptable evidence of student understanding, and 3) planning learning experiences. The goal is to develop deep student understanding rather than superficial content coverage. Key aspects include defining big ideas, assessing for understanding, and creating units that hook students and allow for application, evaluation, and differentiated learning experiences.