The document discusses principles and models of curriculum development. It describes the need for curriculum development due to changing educational goals and societal needs. Two prominent models are explained - Tyler's 4-step model involving determining objectives, experiences, organization, and evaluation, and Taba's 7-step model starting with identifying needs and ending with evaluation. The document also outlines principles of curriculum development, types of curricula including subject-centered and student-centered, and the stages of the curriculum development process.