In Japan usually written OVA. Anime created specifically for release on Home Video (Video, Laser Disc, DVD). The first OAV was released on 1983 (Dallos).
The method of writing Japanese with roman characters is named romaji, in essence the English alphabet is used phonetically in place of hiragana, katakana, and kanji. Romaji is not used a lot in Japan, it is highly ambiguous due to the number of homonyms in the Japanese language, so only beginners usually prefer to see Japanese this way, while those more advanced prefer to see real Japanese text.