What constitutes plagiarism?
Not citing sources properly, similar usage of sentences, directly copying from source, etc
Using a bibliography is important. Not only does it let the reader find the sources, but it prevents you from being charged with plagiarism. Also, when citing a quote cite the author's last name and page number (if available), For an example: "Dogs don't perspire by sweating instead they pant with their tongue(Adam 7)." If there is no author cite the web page name like "claims CNN" or "states the BBC" or "according to the CDC."
Even when paraphrasing one must cite the source too. And if you change up the wording a bit, remove a word or two you still can't sell it as your own.
Plagiarism is using some else's work or words without giving the original author credit, and or pretending that their work is yours.
Students are often guilty of plagiarism when they take whole paragraphs or even an entire article off of the internet and present the work or words as their own to complete an assignment.
Students need to be careful when using Socratic answers. To quote the answer provided in its entirety without noting where the answer came from is plagiarism.
It is not plagiarism if the student rephrases the answer in their own words. Combining the answer with some of the student's own work is not plagiarism if the answer is only a small part of the entire article. But it is always best to avoid any appearance of plagiarism by noting when the information was obtain. This can be done with footnotes or in notes at the end of a chapter or article.
The Bibliography should always give a complete list of all of the sources used in the article or work.
Personal Note as a teacher I would google the articles cited in the Biblography as well as the Title and subject of the student's assignment. If I found that the student had used whole sections or an entire article I would fail the student with opportunity to make up or repeat the assignment.