The most blatant form of plagiarism is taking en entire piece of writing and claiming it as your own work. Some examples include downloading an article, reformatting it and submitting it as your own, buying an essay from a paper writing service, taking a free paper off the Internet and turning in another student's work as your own.
It is unethical to take chunks of material from another source and splice them into your paper without acknowledgment. Even if you change some words, it would still be plagiarism. By taking a statement out of its original context and forcing it into yours, you make a source seem to say something that it really did not.
Borrowed material must be documented. Even if you use information accurately and fairly, do not neglect to cite the source. Correctly summarizing a passage and not citing it is still plagiarism.
Use the exact wording of a source and failing to enclose it in quotation marks is considered plagiarism. Whether it is a paragraph or a phrase, enclose the wording from the source in quotation marks. When you get a quotation wrong or paraphrase a source poorly, you misrepresent the original text.
Through carelessness, often in note-taking, you may confuse borrowed material with your own thinking. Failure to indicate that the material was borrowed, whether by mistake or otherwise, is still plagiarism.