What is Plagiarism?
In short, plagiarism is defined as using the ideas or writing of another as one's own without giving proper credit.*
You might be wondering, why all the worry about plagiarism? Passing off the creative property, ideas, writings, images, etc. without giving credit compromises the integrity of your own work, as well as that of UCSD or any work environment.
*The American Heritage Dictionary of the English Language. (Boston: Houghton Mifflin, 2000), 9 December 2008 <http://www.bartleby.com/61/>.