Ancient poetry: The so-called ancient poetry refers to the poetry forms with less metrical restrictions formed before the Tang Dynasty, including four-character, five-character, six-character and seven-character, which generally rhymes, does not pay attention to flatness, and has unlimited sentences. The development track of classical poetry: The Book of Songs → Chu Ci → Han Fu → Han Yuefu → Wei, Jin, Southern and Northern Dynasties Folk Songs → Jian 'an Poetry → Tao Poetry and other literati five-character poems → Tang Dynasty Ancient Style New Yuefu. Among them, Cao Cao's Looking at the Sea is one of the classics. Modern poetry: Modern poetry is a new poetic style that appeared in Sui and Tang Dynasties. There are two kinds of poems: quatrains and metrical poems. Metric poems are usually eight sentences (more than eight sentences are called except or long), which are divided into first couplet, parallel couplet, neck couplet and tail couplet. The quatrains are four sentences. According to the number of words in each sentence, it can be divided into five laws, seven laws, five sections and seven sections. It pays attention to the level of rhythm, rhyme and antithesis. Except for arrangement, the number of sentences is limited. The most striking feature of modern poetry is its neat structure, exquisite rhyme, and even and neat style. Therefore, Yuefu poems, metrical poems, words, songs and fu should be counted.