Plagiarism may be accidental or blatant and there is even self-plagiarism.
Accidental or Unintentional
One may not even know that they are plagiarizing. It is the authors responsibility to make certain that they understand the difference between quoting and paraphrasing, as well as the proper way to cite material.
Blatant
Here, authors are well aware that they are plagiarizing. Purposefully using someone else's ideas or work without proper acknowledgment is plagiarism. This includes turning in borrowed or bought research papers as one's own.
Self
Turning in the same term paper (or substantially the same paper) for two courses without getting permission from one's instructor is plagiarism.
Plagiarism, data fabrication and image manipulation are not tolerated.
Plagiarism is not acceptable in Risks submissions.
Plagiarism includes copying text, ideas, images, or data from another source, even from your own publications, without giving any credit to the original source.
If plagiarism is detected during the peer review process, the manuscript may be rejected.