Different occasions require different writing styles. For example you may need to write an APPRAISAL in Cooking but a SCIENTIFIC REPORT in science. Each of these need different parts and different writing styles.
Audience and Purpose. When you communicate, your purpose is not what you want to do; instead, it is what you want your audience to do as a result of reading what you wrote or listening to what you said. Thus, it involves the audience. ... Knowing your purpose and audience helps determine your strategy. Something about purpose and audience....