In the complicated situation of the Corona epidemic, most schools at all levels in some countries with many infections are closed and students are allowed to stay at home. However, due to the long absence from school, it has more or less affected the learning of pupils/students in general. Faced with this situation, online learning applications were born, helping students not have to go to school but still gain knowledge from teachers.

Good live-streaming video applications that allow pre-recorded videos are quite popular and used by many teachers. In China, Alibaba's DingTalk application is used as not only a workplace, exchanging information between employees in the company, but now also a place of learning and knowledge exchange of more than 12 million students. in this country of billions of people. Although they have to learn through online live-streaming applications, these applications still receive a lot of response from students. A lot of positive comments are left on this e-learning platform.