Academic conferences play an important role in scientific researches.
However, it needs much time and money to take part in a conference. Thus we can only join those conferences which are most important to us. With development of internet World Wide Web, it is possible to take part in a virtual conference online. Although thus a conference is not as direct as a real conference, it has the advantages of saving time and money, easily organize, more people around the world can freely take part in, and help us to catch the most new and widely research projects. It is free.