Online education, as the name implies, is the teaching method based on network. Through the network, students and teachers can carry out teaching activities even if they are separated by thousands of miles. Online education content can be online courses, online textbooks, online research articles or videos, etc. It takes a variety of forms.

Open educational resources (OER) are teaching and research resources that are released under an intellectual property license to be freely used and reused by others in the form of books, videos, tests or quizzes, and any other tools, materials, or techniques used to support the acquisition of knowledge.

For the openly educational content, each course or resource displays an open license. Open licenses reserve certain rights and relax others, making it easier for educators and curriculum designers to use these resources. If we want to access, copy, or adapt open content, an open license means that the resource is free for you to use whenever you want.

EdX is a famous open educational resource, which was recommended to me by the professor of mathematics in China at the beginning. It is an online teaching program jointly launched by MIT and Harvard University in May 2012. The main purpose is to cooperate with campus teaching, improve teaching quality and promote online education. The platform is popular not only abroad but also in China. Several prominent Chinese universities are involved, including tsinghua university, Peking University, the university of Hong Kong and the Hong Kong university of science and technology.

The guide for evaluating open educational resources are mainly divided into six aspects,which are relevance, accuracy, production quality, accessibility, interactivity and licensing. As we can see on the official website, edx contains many popular subjects, such as computer science, linguistics, finance and management, engineering, anthropology and so on. You can also use the search bar for the keywords you are looking for, and each subject is related to many useful resources. I have been using edx for nearly 4 years, and I have not found any major mistakes in its resources. As mentioned above, it is an online learning platform built by more than 140 universities around the world, which shows its official nature and credibility. The layout and interface operation of edx make people clear and easy to understand. It puts the key words of subjects that users search more on the homepage, and users can see these information directly. In addition, the search bar is highlighted in the center of the screen instead of the upper right corner. When we choose a want to learn the subject, to the left side of the interface gives us more options, such as the time of publishing, the level of the course, (introductory intermediate or advanced). This allows users to better according to their own situation to choose courses

Most importantly, on edx, we can choose the language of the course, not only English, which also gives users more opportunities to learn. This may be the magic of OER. Users can choose their favorite or familiar ways or languages to achieve the most effective learning methods. All videos on edx can be subtitled, so there is no need to worry about not hearing any sentence clearly. Users can achieve the highest learning efficiency through visual and auditory effects. If you are not registered or logged in to edx, you can still use the above resources, the video will be presented in the form of YouTube video, users can subscribe to YouTube.

In the entry interface of each course, the system will tell you how many students have registered for the course. This number is a powerful number, just like in school. These are the students you study with, which also increases our enthusiasm and participation in learning. For the licensing, edx allows users to download or share resources, and edx displays its own icon on the main screen, as well as the icon of the university offering the courses, so ownership of educational resources is legally recognized.

Finally, I believe that OER changes the way we learn, enabling all-round communication through the Internet to improve learning efficiency. Anyone, anytime, anywhere can learn. OER plays a dominant role in both learning and work in the future, making full use of resources. For me, when I choose OER, I will find that I can record all the teaching content. If I am not clear about some knowledge, I can watch the teaching content repeatedly and improve my learning ability and review ability.