OVAs are often shorter than a normal episode of the show, while Specials are often as long or longer, although this definitely doesn't always hold
An episode length of 30 minutes occurs quite commonly, but no standard length exists OVAs are generally released for home video (be that VHS, DVD, or whatever), whereas it's possible for a Special to be released as a television broadcast that is just separate from the rest of the show. Episode length varies from title to title: each episode may run from a few minutes to two hours or more. OVA media (tapes, laserdiscs or DVDs) usually contain just one episode each.
OVA DEFINITION ANIME TRIAL
These can be treated as a type of reward made by the makers or more like a trial just to see the response of the watchers Like anime made for television broadcast, OVAs are sub-divided into episodes. OVAs, then again, are non-chronic or non-canonical in nature and might have any connection with any current TV anime series. Source: (CC BY-SA 4.0 Original Animation Video (OAV/OVA) Original Animation Video & Original Video Animation (OAV / OVA) are interchangeable terms used in Japan to refer to animation that is released directly to the. This includes both whole series first sold as discs, as well as bonus episodes that never aired on TV but on blu-rays containing episodes that did air on TV. Most anime shows are released for television first (in Japan) and then released on DVD later, but OVA's are the reverse An OVA is an anime that was released first as physical copies, that is, on discs, DVDs, Blu-rays, as opposed to having first aired on TV. OVA's are episodes produced exclusively for video release, though they usually air on television a few months later. Original Video Animation (or OVD - original DVD animation).