What do the couplets in the poem mean?

The first couplet of the first couplet

The second couplet of the chin couplet

The third couplet of the neck couplet

The fourth couplet of the tail couplet

In quatrains (four lines to a poem, such as Li Bai's "Quiet Night Thoughts"), each punctuation mark (comma, period) is a couplet

Rhythm poem (eight lines to a poem, such as Li Bai's "Huang "Crane Tower"), each period is a couplet

It is easy to remember that the head is the top of the head, the chin is the chin, the neck is the neck, and the tail is the end