Note: For any technical document (paper/article, report, thesis dissertation), simple and formal language style must be followed.
One small paragraph on what this paper is about.
One or more paragraphs on the details of issues that got raised in the previous paragraph.
Over a few paragraphs, general review of literature in the field with special emphasis on aspects important for the present paper. Important: Use 'your' appraisal regarding others' works, use absolute/standard terms, DO NOT LIFT lines from their papers. Be critical in your comments, but fair. DO NOT take published papers at face value.
A few paragraphs more to identify gaps and lacunae in the literature, so that the present work seems to be really warranted.
One paragraph to clearly specify the exact issue that the present paper addresses - in more concrete terms than the first paragraph of this section or the abstract.
A brief sectionwise outline of the paper - starting from the next section.
Note: Paragraph structure outlined above is flexible.