SP: 1) In Japanese animation, usually after the news is released, because the market response is very enthusiastic, special chapters will be released in order to make money, that is, SP. Here SP is the abbreviation of スッペシャルSpecial, which means two A special chapter of about an hour. The fact that it appears with OST here probably means this.

2) The pinyin abbreviation of video (Shi Pin); 3) The so-called "SP", that is, Standard-Playing, the vinyl record was 78 rpm in the early days of its birth. But soon 33 rpm LP (Long-Playing) vinyl records came out, and almost all the records in existence today are LPs, so later vinyl records were directly called "LP". OST is the abbreviation of Original Sound Track, which literally means the original sound track (film and television original soundtrack), which is the track that stores background music (or songs) in all audio tracks of the movie. Because it is a noun in movies, it is also called movie soundtrack or movie soundtrack. OST generally refers to the soundtrack (Score) or song in the movie.