A couple of years ago, individuals can only take courses at real schools。 In other words, only when they go out to schools by themselves will they have lessons which they want to have. However in recent years, with the development of internet and education mode， online teaching has become increasingly common. This kind of teaching mode means that a student just needs to have classes sitting in front of a computer at home， which appealing to lots of people。 It is widely acknowledged that online teaching has its apparent merits。 First and foremost, shared resources online are accessible to all people, which costs a little at the same time。 This feature brings about significant benefits especially to those who fail to afford that many courses at real schools。 Secondly, online teaching makes it come a reality that one is able to study at the best pace suitable for him according to his own schedule. Last but not least, studying at home without going out is much more comfortable as well as convenient to busy people in contemporary society.Meanwhile， there is no denying that online teaching also has demerits that cannot be dismissed. For one thing ， online teaching, not like face-to-face teaching ， lacks interaction between teachers and students， causing teachers not to receive feedbacks from students in time。 For another thing， for people who are poor at self—discipline, learning online at home will be a less effective way since they are easier to be distracted by other things. Besides, all of online teaching courses are ready—made rather than custom-made, that is to say, it is troublesome to be flexible when changes are needed。
