Plagiarism

Plagiarism is the act of representing someone's words, facts, or ideas as your own.
In practice

back
you may not
turn in anything written in whole or in part by someone else as your own;
.
you may not consult a complete paper on a topic like “Witchcraft in Harry Potter” and make the same points on this subject, even in your own words;
.
you may not use your computer to “cut and paste” part of someone else's writing into your own without paraphrasing or using quotes, and identifying the source.