<p>This article provides a detailed explanation of the concept of “plagiarism” and its main types. It also examines the distinctive features of the scientfic term “self-plagiarism” in comparison with plagiarism. Both plagiarism and self-plagiarism are considered violations of scientific ethics; plagiarism, in particular, is regarded as an illegal act that infringes copyright and intellectual property rights and may entail corresponding sanctions. It is noted that such practices in the scientific field can cause mistrust, cast doubt on the reliability of results, and lead to the loss of a researcher’s academic reputation.</p>