Most often the phrase scientific writing is used to refer to reports of original research in journals. It may also, however, be used in reference to other kinds of writing such as review articles (which summarize and synthesize previous research), annotated bibliographies (which aid others in performing research), abstracts (which summarize experiments or studies), and grant proposals (which seek funding for research). In any case, the point of scientific writing is communication by a scientist with an audience of peers. Since the purpose is communication and not entertainment, scientific writing should be precise, clear and objective.
This guide is primarily intended to help with the first type mentioned above: a report describing original research results.