Parallelism, also parallel construction or parallel structure. Frequently, this works as an organizing force to attract the reader's attention, add emphasis and organization, or simply provide a musical rhythm.
This term comes from Greek roots meaning "beside one another." It refers to the grammatical or rhetorical framing of words, phrases, sentences, or paragraphs to give structural similarity. This can involve, but is not limited to, repetition of a grammatical element such as a preposition or verbal phrase. A famous example of parallelism begins Charles Dickens's novel A Tale of Two Cities: "It was the best of times, it was the worst of times, it was the age of wisdom, it was the age of foolishness, it was the epoch of belief, it was the epoch of incredulity..."