Plagiarism is "the action or practice of taking someone else's work, idea, etc., and passing it off as one's own" or also know as "literary theft" (OED Online).
It is a form of lying, cheating, theft, and fraud.
It is not a form of copying and borrowing -- that is a common misconception.
Plagiarism is a very serious offense.
"plagiarism, n." OED Online, Oxford University Press, March 2022, oed.com/view/Entry/144939. Accessed 9 March 2022.
Many things can be considered plagiarism. Here are a few examples (From Plagiarism.org):
“What Is Plagiarism?” Plagiarism.org, Turnitin LLC., 2017, plagiarism.org/article/what-is-plagiarism. Accessed 9 March 2022.
Here are more-detailed descriptions about these types of plagiarism.
Essentially copying the entirety of someone's work and labelling it as your own This is the most serious type of plagiarism! "It is equivalent to intellectual theft and stealing."
Sometimes plagiarism happens because of a source. Here are a few examples of source-based plagiarism.
Misleading citation - When someone cites a source that is wrong or doesn't exist.
Misdirecting citation - When someone fails to cite a source's source, only citing the first source; or uses a child citation of a parent citation and only cites the parent citation.
Data fabrication - When someone creates false data and research.
Data falsification - When someone deliberately changes or omits data to get the results they want.
Essentially copying a section of someone's work and pasting it into your own. It is like complete plagiarism except it is only a section rather than the whole thing.
When you use a portion of work you previously created in another project and don't cite yourself.
Basically rewriting someone's sentence(s) as your own, maybe making some minor word and grammatical changes. Just because the words are different doesn't mean the idea changed. This is one of the most common types of plagiarism!
This can happen on group-developed content, either when someone does the work but gets no credit OR when someone does not do the work and gets credit.
This "may be more difficult to detect because it interlays someone else’s phrases or text within its own research. It is also known as patchwork plagiarism and it is intentional and dishonest."
This can happen a lot. People may be plagiarizing without recognizing it and sometimes face the same consequences as the people who do recognize they are plagiarizing. Usually accidental plagiarism happens unintentionally or as neglect or a mistake.
"8 Most Common Types of Plagiarism to Stay Away from!" Enago Academy, 26 November 2021, enago.com/academy/fraud-research-many-types-plagiarism/, Accessed 10 March 2022.
Most plagiarism cases are avoided if you cite your sources!
If you are ever unsure if you are plagiarizing, get a second opinion. Share what you wrote -- including the source you used -- with your instructor, a librarian, a writing center staff member, or other trusted individual.
When in doubt, always cite your source! Check out the Citation Style Guide for how to create and format a citation.