What Does Video Buffer Mean?
A video buffer is a portion of a computer's physical memory that is used to store video or graphics information as it moves from the renderer (video card) to the display screen or monitor. As with buffers in general, the video buffer is used to organize data and to ensure that the data are efficiently moved from their source to their destination; although it has many similarities to the system cache or the video memory, it is separate from both.
The video buffer is also called the screen buffer or the regeneration (regen) buffer.
Techopedia Explains Video Buffer
The video buffer, like all buffers, collects and stores information in a physical memory for later movement, basically acting as a waiting area so that when the information is required it is already processed and ready for consumption and application. The video buffer thus stores data in anticipation of its need, so when that information is finally required it is ready to move to active memory.
The video buffer gathers all information that describes all the visual elements that will appear on the user's screen such as menus, windows, images, videos, etc. A big reason for having a video buffer is so that everything on the screen appears seamless and the transition is smooth since in-memory processing is faster than on-screen processing. Using a video buffer thus allows screen content to be processed before use so that it does not need to process when the actual data are required.