Original Video Animation (OVA) refers to animated works that are produced specifically for home video release, rather than being shown in theaters or on television. OVAs can vary in length, often consisting of a single episode or a series of episodes, and they may be adaptations of existing manga, light novels, or video games. These productions often allow for higher quality animation and storytelling, as they are not constrained by broadcast schedules or advertising. OVAs can appeal to niche audiences and are sometimes used to expand on popular series, such as those featuring characters from anime or manga.