The document discusses key concepts of the theory of didactic situations, which analyzes the learning process through the interaction between the student and a problem or question presented by the teacher. The theory focuses on three stages: first, the teacher presents a problem or question (situation); second, the student engages in problem-solving actions (formulation); third, the teacher evaluates and provides feedback on the student's solutions (validation). The teacher may then modify variables of the initial situation based on this evaluation.