A writer’s “voice” is how the writer’s words sound in the reader’s head. I tell my students that it you do it correctly, it’s like a magic trick: I have implanted in you, the reader, my words said in the same way that I hear them in my own head. When that actually works? Now that is a voice.

Writer voices—much like a singer’s voice—will vary from task to task and job to job. This is where it gets important. A good writer will switch up her voice to meet the job at hand; a good editor will be able to smooth out the words on the page to shape them into the voice that’s needed.

A government proposal, for example, needs a firm voice that implicitly builds confidence through its clearly stated knowledge. A client report will need a similar voice but will usually more explicitly exude and build confidence through its command of the project. An article for an employee magazine or an employee report, meanwhile, might have a more casual tone that reaches out to the reader and envelopes him or her in a quiet written conversation.

Still wondering about the power of voice? Try this little exercise: Imagine an email where you are inviting a friend to meet you for coffee tomorrow. Now imagine a text with the same purpose. They’re different, right? Because our email “voice” is different from our texting “voice.”

Now really spin the exercise on its head: imagine you are emailing your boss to invite him or her to coffee. The voice changes again, right? Your audience is a big part of deciding what voice to use.