Light equipment education is online video education. Official website has a full set of videos, which can be watched on demand anytime and anywhere. At the same time, if you watch it on your mobile phone, you can cache it, and then there will be no traffic when you watch it. Even if there is no network, you can study. This method is much better than CD-ROM and has obvious advantages. The disadvantage of optical discs is that they are easy to break tracks. The optical drive must look at the optical drive, which is easily damaged by the outside world and needs good protection. Moreover, it is also very common that the CD will produce bad tracks, cards, mosaics, loss of sound and unobservable phenomena after watching it for a certain number of times.