Citation is an important step in the research process because it's a way to prove the the credibility of your work. Students often express concern that excessive citation might reveal lack of original ideas, when in fact acknowledging and crediting other researchers substantiates your own work, and shows that you're a responsible scholar. Citing your sources also extends the scholarly conversation because you're providing the context of your argument within the academic field of study.
We also cite sources to avoid plagiarism, which the CSUSM Academic Honesty Policy defines as:
Intentionally or knowingly representing the words, ideas, or work of one's own in any academic setting including:
(a) the act of incorporating the ideas, words, sentences, paragraphs, or parts thereof, or the specific substance of another's work, without giving appropriate credit, and representing the product as one's own work;
(b) the act of putting one's name as an author on a group project to which no contribution was actually made; and
(c) representing another's artistic/scholarly works such as musical compositions, computer programs, photographs, paintings, drawings, sculptures, or similar works as one's own.