It's a place for spontaneity, experimentation, creative and emotional risks. The diary is the safe place where you develop your voice as a writer. It can be a sourcebook for other creative work, an emotional catharsis, an ongoing letter to oneself or to the world. Generally, diaries are difficult to publish unless you are famous or notorious and dead. Nevertheless, you can learn how to edit a diary so that it will be readable if you want to try to publish it.
Autobiographic writing requires more knowledge of craft than diary writing does.
Once you have settled on the genre or genres of the self you wish to work in, you can learn the techniques appropriate to it. Many people know they have a story within their life worth telling, but they think they don't have the self-discipline to write it. They get lost and frustrated in the process. Fortunately, the craft of autobiographic writing can be learned, and we are here to help. With the correct tools you will be able to write about your life so that others will be riveted, enthralled, moved, even changed.