They have different formats. Rhymed poetry has a fixed form and strict rhythm. Each poem has eight sentences. A single sentence is called a sentence, and a double sentence is called a couplet. The first two sentences are called couplets, the third and fourth sentences are called couplets, the fifth and sixth sentences are called neck couplets, and the seventh and eighth sentences are called tail couplets. Couplets and neck couplets usually have to face each other. The first sentence must have rhyme, usually flat rhyme. Five characters are called "five character verses", seven characters are called "seven character verses", and ten or more sentences are called arranged verses.
Ancient poetry has four characters, five characters, six characters, and seven characters. Later generations used more than five characters and seven characters. Five characters are called "Five Ancients", and seven characters are called "Qigu". Ancient poems do not limit the number, do not require confrontation, do not talk about equivalence, and use rhyme more freely. The original meaning of ancient poetry refers to the poetry created by ancient scholars. They have unique expressions and artistic styles and are collectively called "ancient poems".
Rhythmic poetry requires that the number of words in the poem should be neat and uniform. Each of them is a five-word, six-word, and seven-word sentence. A typical poem requires eight sentences. If there are only six sentences, it is called a short rhythm; if there are more than eight sentences or more than ten sentences, it is called a long rhythm or a long rhythm. The meter and rhythm of poetry are very strict, and there are strict regulations on the number of sentences, the number of words, rhyme and rhythm.
Ancient poetry with five characters in each sentence is a poetry style formed during the Han and Wei dynasties. It has no certain rhythm, no length limit, does not care about obscurity, and uses rhyme quite freely, but the number of five words per sentence is fixed. Because it is different from the Yuefu songs of the Han Dynasty, and also different from the modern poetry and quatrains of the Tang Dynasty, it is called "ancient five-character poetry".
Rhymed poetry is a type of modern Chinese poetry. The meter is very strict. The new poetry of Qi Yongming and Shen Yue, which originated from the Southern Dynasty, and emphasized rhythm and parallelism, formally took shape in Shen Quan period and Song Zhiwen period in the early Tang Dynasty. It was fully mature during the Tang Dynasty. Rhymed poetry requires a consistent number of words in the poem.