About Writing

Brainstorming, like freewriting, is a prewriting technique designed to bring subconscious ideas into consciousness. It's a good technique to use when you know a general subject you're interested in writing about but don't exactly know what aspect of the subject you want to pursue. Brainstorming is like a stream-of-consciousness technique in which you rapidly record all ideas related to a general subject. All ideas are equally acceptable; the purpose of brainstorming is to identify as many ideas related to the subject as possible.
Most likely you have either experienced brainstorming in a business setting or have seen it portrayed on television or film: the ad exec holds up a product and says to the advertising team, "All right, people, let's pitch ideas to sell this soap!," and a person standing by a flip chart jots down ideas frantically as employees shout them out.

Freewriting

Freewriting helps you identify subjects in which you are interested. It assumes that you know your interests subconsciously but may not be able to identify them consciously, and it assumes that you can bring your interests into consciousness by writing about them (as writing equals thinking). Freewriting is like stream-of-consciousness writing in which you write down whatever happens to be in your thoughts at the moment. After you do a number of freewritings, you may find that you have come back to certain subjects again and again. Repeated subjects are good for further development through writing, as they obviously are important in your thoughts.