Video on-demand has to do with the delivery what they call content, while the video phone is the deliver of person-to-person communication. These are not nearly the same, but they both involve video.

随需视频必须与传送他们所称的“内容“相关,而视频电话是一种,个人对个人的传送，那不是,大致相同的，但它们都包含视频。

麻省理工公开课 - 媒体、教育、市场课程节选

I take the time and put it in the y equation and demand that the y I get, agrees with this y.

然后我把时间代入 y 的方程,令得到的 y 的表达式等于这一段的 y

耶鲁公开课 - 基础物理课程节选