When I read about writing style, I also find tone and voice included in the discussion as elements of style, but to me they are three separate entities.

Style

I often read that writers should develop their own unique signature styles, but I think writers select different styles for different projects, and sometimes even for different parts of the same piece. To me, style is made up of the writing techniques the author employs, for example, the vocabulary he chooses, the length of his sentences and paragraphs, whether he writes in a didactic fashion or a more conversational mode. I think each author makes style choices consistent with what the project requires.

If she’s writing a scientific piece, she’s probably going to use scientific terminology, and possibly include definitions depending on who her intended audience is. Her paragraphs might be longer, structured with a topic sentence and several supporting sentences. An occasional short paragraph might be inserted to make an important point stick out.

For a humorous sketch, her vocabulary and sentence structure would likely be less formal and more conversational.

Or for a how-to, the writing should be clear and concise, laying out steps to follow to achieve a desired result.

In poetry, she might utilize literary devices and wordplay in her style.

Tone

Tone is the mood that the writing evokes. For example, in mystery or suspense, the tension keeps building. Romance may be erotic. Humor should be funny, satire wry. Okay, I can see how style impacts tone. But is tone a part of style, or an effect of it?

Voice

I believe voice is unique to the writer, but I also think a writer’s voice changes with the project, unless the writer specializes in one genre. I think I have a distinctive personal voice in my blog posts, but in my fiction, I’m more concerned about the character’s voice than my own—and each character should have a distinct voice.

Voice also depends on how words are put together and how sentences and paragraphs are structured, but voice also reveals something about the writer—or the character. For example, regional expressions may be part of the word choices, or the views expressed may be strongly influenced by one’s religious heritage. I could say that voice goes deeper into personality than style does. Okay, I can see how voice can influence style, but is voice an element of style, or an entity that stands adjacent to it?

Style, tone, and voice are like a trinity that collaborates on literary creations.