Metric poetry, also known as modern poetry, is the most prosperous form of poetry in the Tang Dynasty. There are five laws and seven quatrains. It is called meter because it has strict requirements on the rhyme and rhythm format of tones.
Classical poetry refers to the form of poetry before the Tang Dynasty, not limited to melody and format. Most of them start with songs, songs and lines, which can be long or short, and can be mixed with four words, five words, six words and seven words.