video the technology of moving or sequenced pictures or images Note Video can be made up of animated or photographic images, or both. video-only a time-based presentation that contains only video (no audio and no interaction) viewport object in which the user agent presents content Note 1 The user agent presents content through one or more viewports. Viewports include windows, frames,
      loudspeakers, and virtual magnifying glasses. A viewport may contain another viewport
      (e.g., nested frames). Interface components created by the user agent such as prompts,
      menus, and alerts are not viewports.