Genre is the type of writing and audience is the “who” of the writing, or in other words the readership of a piece of writing. These two terms are interconnected in many ways.
The genre of the writing, such as whether to write an article or a personal essay, can be determined by looking at the audience for that particular piece of writing. For example, if the audience for a piece of writing is a professor, or a high ranking official in a firm, then the genre chosen would normally be a formal essay or letter, whereas if it was a younger audience, the genre would more likely be a blog post or a personal essay.
Some other examples of genre include a blog proposal, or a research log, which comprises of collecting different sources and writing short summaries on each source.
Genre can also help determine audience. For example, the readership of a scholarly article would comprise mostly of an older audience, whereas a comic strip as a genre would attract a much younger audience.