The abstract is the most visited part of the article that people can view for free. the abstract is a separated part of the paper and shows information about the introduction, research questions, methodology, results, and recommendations. Therefore, readers should be correctly aware of the main content of the whole article by reading a 150- to 250-word abstract. LaPlaca et al. (2017), describe three main types of abstracts: the indicative (descriptive), informative, and structured abstract.
the indicative abstract includes the topics papers, and the readers could be aware of what in the main body written. In the case of informative abstracts, the author implicitly reports the sections of the paper from beginning to end, without naming the sections (introduction, methodology, data analysis). Finally, the structured abstract tries to fill in the items in the form, based on the required structure of each journal. Some journals ask authors to separate the managerial/executive summary from the research abstract or to explain in one or three lines only the methodology.
All journals have guidelines for abstract writing that authors should submit their papers according to the considerations of that. A very important point is that the abstract is written after the research is completed and should cover the whole paper. There is no reference in the abstract and no unusual expressions are used. Abbreviations must also be written in full first.
As a last note, a clear and accurate abstract saves the reader time and includes the necessary information that highlights the attractiveness of the paper.