Try to apply this question to your everyday life as a writer. When you write academically, you're typically writing things along the lines of essays. These essays have prompts and topics you have to write about specifically. This type of writing is done more professionally, unlike personal writing. Personal writing is basically anything you write for yourself, about yourself, etc. Less professional, in a sense. Personal writing doesn't need to have perfect grammar and spelling and isn't usually for a grade. However, both academic writing and personal writing are great ways to express information, opinions, feelings, emotions, etc. just like any type of writing.