Onyomi refers to the Chinese readings of kanji, the characters used in the Japanese writing system. These readings were adopted from Chinese during various historical periods, leading to different pronunciations based on the time and region of origin. Onyomi is often used in compound words, where two or more kanji are combined to create new meanings. In contrast to kunyomi, which are the native Japanese readings of kanji, onyomi provides a way to understand the influence of Chinese language and culture on Japanese. Both readings are essential for mastering Japanese and reading various texts, as they contribute to the richness and complexity of the language.