Research articles are also often known as scientific or peer-reviewed articles. If the article is NOT written by the person or group who did the research, it is NOT a peer-reviewed or scientific article. Research articles are important for knowing what new discoveries have been made. This is why it is important to use recent articles, since they will be the first things published on a new scientific development.
Here's a quick overview of how to identify these journal articles:
If a book or article you want is not available, use Interlibrary Loan (ILL). The Library can order books and articles from other libraries. This process takes few days but is completely free for DelVal students, faculty, and staff.