Description: In this study five teacher educators and eight teacher trainees were interviewed about how they interpret one of the objectives in the curriculum for the teachers' education in Sweden. The objective concerns teaching and learning "to transform good and relevant knowledge in subjects and subject areas so that all students will learn and develop". The study has its base in the phenomenographic approach and the theory of variation. The contextual analysis of the transcripts reveals six conceptions of teaching and learning. The conceptions are summarized in the following categories of descriptions: I: "Teaching happens in schools" II: Subject-teacher is an entity III: The student is included; the subject is transformed IV: The subject is exposed to the student V: Student's prior knowledge is related to the concept structure of the subject VI: Thoughts are the content of the teaching Relations between the conceptions and their aspects, the architecture of the variations, are described in a system of the concepts, which has the form of a stair case and it is therefore called "The Stair case of Teaching". The stair case of teaching shows how the qualitatively different conceptions of teaching increase in complexity and how the new aspects of each conception will color all the aspects of the previous conception. The aspects are subject, the role of the teacher, the role of the student, learning, the structure of the concepts and relation thought-subject. In the study five qualitatively different meanings of the concept learning are described. The outcome space of the six categories of description shows how the teacher educators and teacher trainees conceptualize the objective in terms of teaching and learning. The result of the study might have important implications for the teacher education in writing course curriculums, students' assignments, criteria for grades, assessment and evaluating reports.