What is the technique of "repetition" in poetry?

Overlapping words, also called overlapping, and overlapping chapters and sentences are a way of expression of poetry, which is also an important feature of The Book of Songs, that is, the syntax of each chapter is basically the same, only a few corresponding words are changed in the middle, and the singing is repeated. The function is to deepen the impression, render the atmosphere, deepen the main body of the poem, enhance the musicality and rhythm of the poem, and express the feelings incisively and vividly. Overlapping means that sentences with the same meaning overlap back and forth.