Plagiarism is using someone else's words or ideas as your own without attribution. Whether or not it's intentional, failure to properly give credit to work that is not yours is considered plagiarism.
Examples of plagiarism (Columbia College Library, 2020):
According to the CSUSM Academic Honesty Policy (Section VI. D), plagiarism is defined as:
"Intentionally or knowingly representing the words, ideas, or work of another as one's own in any academic exercise, 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.
The policy also provides the following guidelines to avoid committing plagiarism: