While each article is different, here are some common pieces you'll see in many of them.
Title
The title of the article should give you some clues as to the topic it addresses.
The abstract allows readers to quickly review the overall content of the article. It should give you an idea of the topic of the article, while also providing any key details--such as the questions address in the article and the general results of the studies conducted.
The introduction introduces the general topic and provides some background information, eventually narrowing it down to the specific issues addressed in the article.
The literature review describes past research on the topic and relates it to the specific topic covered by the article. Not all articles will have a literature review.
The methods section addresses the research design and methodology used by the author to come to the conclusions they have in this article. This gives others the ability to replicate the study. Not all articles will have this, since there will be many articles that don't involve an actual study.
The results section presents the results of any studies or analysis that has been conducted. Not all articles will have this, either.
The discussion/conclusion addresses the implications or future of the field. It may also address where future research is needed.
The list references or bibliography is the alphabetized list of resources used for the article. The format of the citations is often determined by what that field's preferred format is. Common citations formats include APA, Chicago, and MLA. This is a necessity in an article--and it helps you identify more possible resources for your own paper.
Useful site that goes more in depth on these sections.
A really wonderful site by the Nash Community College Library.