视频点播（VOD）指能在用户需要时随时提供视频服务的业务。目前电视广播中，收看者是完全被动的，节目单是别人定好的，放什么内容，你就只能看什么节目，可能你在各台之间寻找了许久也找不到一个爱看的节目。节目播放时间也是别人定好的，好节目也许总是在你无法收看的时间内 Video on Demand (VOD) refers to the business that provides video services whenever the user wants it. At present, in the television broadcast, the viewer is totally passive, the program list is set by others, what content is put on and you can only watch what programs, maybe you look for a long time between the stations and can not find a program you love to watch . The show time is also set by others, a good show may always be in the time you can not watch