A video server is a server that is dedicated to taking in, storing and delivering video. Like other types of servers, a video server is typically a physical hardware unit that fits into a standard 19-inch rack space and can be connected for direct input and output.
Techopedia explains Video Server
Video servers use specific technology to catalog and store video clips or full-length videos, and to distribute them as needed. These technologies include codecs and transcoding tools, as well as broadcast quality features to ensure high-quality streaming digital video. Video servers also typically use metadata to fully document the identities of video clips for efficient distribution.
As a digital video storage resource, the video server has revolutionized broadcast industries. Where the norm used to be bulky analog video reels in metal jackets stored on large shelving units, broadcast entities can now store hours of video in a standard-sized video server. These pieces of hardware can also facilitate automated video broadcast, where a large amount of human labor is avoided. Client programs can achieve highly automated broadcast methods with a high-quality video server infrastructure.