Abstract
The abstract is an overview of the entire research report/study. They vary in length, but the goal of the abstract is typically to help a reader know if the paper is relevant to their work and worth reading in-depth.
Introduction
The introduction provides context and background to the topic at hand, provides a summary of existing literature on the topic, and provides an overview of the study being described.
Methods
The methods section describes how the research was performed. This includes a description of the participants, the study design/methodology, materials used, and study procedure.
Results
The results section describes the data that were collected and any statistical tests that were performed.
Discussion
The discussion section describes the significance of the work in question. This typically includes a summary of the results and how those results address the research question. Limitations of the study and directions for future research are often included.