What do the three pinyin festivals and the four pinyin festivals mean?

The syllables of Chinese Pinyin are usually two syllables composed of an initial and a vowel, and some syllables are composed of an initial and two vowels. This kind of syllable is called a trisyllabic syllable. Like Liao. Four Pinyin Festival is a syllable consisting of one initial and three finals, which is generally used to spell foreign words and minority languages.

Fairy and couplet are a three-syllable festival, which consists of initials, finals and intermediate sounds.

Two pinyin stanzas are syllables consisting of an initial and a non-intermediate vowel. For example, liu, the initial is L, the vowel is iu, and there is no intermediate sound (although there is I in liu, the iu here is connected together and is a compound vowel)