From a lovely essay about using notebooks, by Elaine Fletcher Chapman:
Most writers I know work from notebooks. I carry mine with me, as Jason Shinder was known to advise, along with a folder of poems I am currently revising. Even on my shorter commutes, I carry the pair. They remind me of my heart’s desire no matter what I am doing or where I am going. Is there a difference between a writer’s notebook, a journal, a commonplace book or a diary? I really don’t think so unless the intent is so named. They address the everyday, the quotidian. They may record lists of books read and unread, grocery lists, quotes, receipts, reviews, found objects, letters, beginnings of poems, lines of fiction, descriptions of art, memories, arguments with lovers, photographs, the flow of tides, phases of the moon, words and their origins, and often momentos.
Read more at The Quotidian, Notebooks, Diaries, and Journals by Elaine Fletcher Chapman – The Best American Poetry.