What is an OVA?OVA is the abbreviation for 'Original Video Animation.' Normally in the anime world, an OVA is telling a story of a longer anime series. The series Magic Knight Rayearth is a good example of this. The tv series ran for two seasons. The OVA is a short retelling of the tv series season one.
Types of OVA's
Sometimes an OVA is telling a short story that happened somewhere along the lines of the anime tv series. A good example of this is Tenchi Muyo. There are a lot of OVA (or special movies) that lay somewhere in the original series.
Tenchi Muyo is also an example of animes that started out as an OVA. Tenchi Muyo started as an OVA and later became a long running series with different seasons. Sometimes the company just wants to test the anime to see if people will like it or not. They won't waste as much money making an OVA rather than a long running series that might get cancelled.
OVA's get a much higher budget than a tv series. Therefore the animation is a lot better and they can develop their characters more in depth. They are allowed to play around the story more than they would on a tv series. These OVAs tend to offer a more in detailed plot of the characters. They can either provide a closer to the anime series or satisfy your curiosity and tell you how the story began.
History of the OVAIn the early 1980s, the VCR became an object in almost every Japanese house. The demand of anime began to rise and direct-to-video VHS' were bought everywhere in Japan. They were mostly buying OVAs. The OVAs were the most easiest to quickly get out onto VHS for the customers. The first 'official' anime to be released as an OVA was Dallos in 1983.
In the 1990s, though, Japan's economy began to fall. The OVAs began to vanish little by little. The tv series also took a hit during this time being only 13 episodes long, rather than the normal 26 episodes long. In the early 2000s and on, the OVAs made a come back. Now the OVA is in demand again.