Which term describes the manner of writing rather than the content written about?

The term that describes the manner of writing rather than the content written about is style. Style refers to the distinctive way in which a writer expresses their ideas, which includes choices regarding word selection, sentence structure, literary devices, and overall approach. It encompasses the author's unique voice and can vary widely across different genres and individual authors.

Diction, while related to style, specifically focuses on the choice of words and their connotations. Tone, on the other hand, refers to the emotional quality of the writing, how the author's attitude toward the subject or audience is conveyed. Discourse generally refers to written or spoken communication and can encompass various types of narrative styles but is broader and not specific to the manner of writing itself. Therefore, style is the most fitting term for describing how something is written rather than what it is about.