From a technical aspect, this thesis represents the development of an online educational system that allows the end users to attend various courses accompanied by various content, while from a visual and user experience aspect the following principles were applied: principles of good design, principles of user-oriented design and finally the principles of design based on understanding the users and their needs, limitations, experiences, goals and desires, with the technology itself representing no more than a learning tool. The ADDIE model was used during the creation of this thesis, encompassing five phases out of which the first phases entailed researching existing educational systems such as Coursera, Moodle and Pluralsight, data gathering and data formatting in order to maximize the quality of later development of the educational system. During the development phase (i.e. system creation phase), Django and Python were used as primary technologies, with others such as HTML, CSS, Bootstrap, JavaScript and SQLite serving to enhance the visual appeal and functionality of the system in general. The final phase consisted of system validation by end users. Usability testing was performed by using an entry questionnaire, problem solving within the system and finally a semi-structured interview. The results of the testing show that most examinees are satisfied by the educational system. They maintain that classic teaching may not be replaced by online courses, but that online courses are still capable of providing enough relevant information and a fine learning experience.