9 downloadable on-line course contents, namely, books or papers in the field of math, English, history, science, Korean, social studies; downloadable electronic books in the field of math, English, history, science, Korean, social studies; downloadable electronic study books or papers in the field of math, English, history, science, Korean, social studies; educational software, namely, software that provides instructions and guides self-learning in the field of math, English, history, science, Korean, social studies; downloadable smart phone application software, namely, software that provides instructions and guides self-learning in the field of math, English, history, science, Korean, social studies; computer application software for digital or electronic tablets, namely, software that provides instructions and guides self-learning in the field of math, English, history, science, Korean, social studies; computer application software for mobile phones for recognition and digitization of image of mathematical expressions; downloadable computer software platforms for accommodating upload, exchange and transaction of educational contents