What does オーブイエー Ova mean?

An OVA is animation released directly to home video, without a broadcast slot or a cinema run. The term is an English-derived initialism used in Japanese, and the format is defined entirely by that distribution route.

Why the format exists

Home video created it. Once households could buy or rent recordings, a production no longer needed a broadcaster to reach an audience, and a work could be made for people who would pay for it directly rather than for a general television audience delivered to advertisers.

That is the whole innovation, and every characteristic of the format follows from it.

What skipping television buys

Freedom from broadcast standards, so content that a network would not carry becomes possible. Freedom from the slot, so an episode can run to whatever length suits it instead of to twenty-two minutes. Freedom from the cour, so a release can be one episode or six without regard to quarters.

Often a higher budget per minute, because the money comes from buyers who have already decided they want it rather than from advertising against uncertain ratings. A great deal of visually ambitious animation reached audiences this way.

What it costs

Discovery. A broadcast series is stumbled upon; a disc has to be sought out and paid for, so the audience is the existing audience. Many of these are made for people who have already read the manga, and they behave accordingly, assuming knowledge and picking up side stories that a newcomer would have no route into.

This is why the format has a reputation for obscurity. It is not that the work is difficult, it is that it was never trying to reach anyone new.

The bundled episode

A common arrangement attaches one to a limited edition of a manga volume, which is a neat piece of commercial design: the animation sells the book, the book funds the animation, and neither has to succeed with a general audience.

For a viewer trying to watch everything, it is also the most annoying possible distribution, since the episodes are scattered across editions of a print run rather than gathered anywhere.

Why the term persists

Streaming has blurred it, and works now appear online that would once have been discs. The word survives because the underlying distinction survives: some animation is made for a broad audience arriving cold, and some is made for people who already know, and the second kind is still built differently.