Does the article cite references?
Is the work subject to peer review (scholarly journals) to determine the reliability of the content?
Does the article contain opinions or facts? Does it reflect the goals of a political, religious, group or institution?
Is the author an expert or specialist in the field.
Is the information sufficiently up-to-date enough for my topic?
You may need to consult multiple sources (journals or databases) to ascertain if there have been recent substantial developments in the field.
Relevance is important because you are expected to support your ideas with reliable information. Does the information in the article answer your research question, meet the requirements of the assignment and add something new to your knowledge of your topic?