SUMMARY
In the article it is presented basic information on the internal structure of modern systems of distance learning, realized with the requirements of international standards in this area. This article is intended for educators (teachers and trainers) to provide the latest information on the basic principles of organization and operation of such systems, which will, in our opinion, design more effectivly subject, including — programmable, distance learning courses, consciously using possibilities inherent in the structure of these systems. The developers of distance education systems can apply the information about data models considered in this article, for the design of new or operation of existing software systems to support distance learning.