Audience, purpose, and context are three key considerations any of communication. You must think about who you are writing to, why you are writing, and what the situation is (yours and theirs). If you consider these three things, your communication will be clearer and more effective. To find out more check out Screen Space 21: The Rhetorical Situation Part 1—Audience and the forthcoming parts 2-4 in the series.
From/Reference: Screen Space 21: The Rhetorical Situation Part 1—Audience