It is important you read the Swansea University Academic Misconduct Procedure. Failure to acknowledge another person’s work (i.e. properly citing it in a paper) will result in serious consequences.
Plagiarism is defined as using, without acknowledgment, another person's work and submitting it for assessment as though it were one's own work; for instance, through copying or unacknowledged paraphrasing. This constitutes plagiarism whether it is intentional or unintentional. For additional advice on avoiding plagiarism complete the online tutorial Academic Success: Skills for learning, skills for life available via Canvas.