Flash Video (FLV) is a container that encapsulates Sorenson Spark, VP6, or H.264 video together with MP3/AAC audio and on‑screen data events for ActionScript. It became the backbone of early YouTube and news portals because the small header footprint yields quick progressive playback. Macromedia introduced FLV in 2002 with Flash Player 6, offering the first ubiquitous plug‑in‑based video experience on the Web. After Adobe’s acquisition, FLV evolved to support H.264 in 2007 but began losing ground once HTML5 gained traction. By the end of 2020, Adobe disabled Flash, and most CDNs convert FLV archives to MP4 or HLS.