PREWRITING
Prewriting is about generating material or ideas or both. Whether gathering information you have inside your head or researching outside sources, you have to start somewhere.
Prewriting is part of the planning stage in the writing process. You must first establish what it is you want to say and why you want to say it. Only then can you proceed to determining how to communicate your ideas.
When we write at work, we write to inform, persuade, publicize and convince: to make a difference to what our readers know. To do this successfully, you must know both the subject and what you want to achieve: i.e., your purpose.