Plagiarism is defined by the University Student Regulations as 'the significant use by a student of other people's work and the submission of it as though it were his or her own'.
The Harvard System of Referencing will provide guidance on how to reference your work correctly and avoid the pitfalls of plagiarism.
There are some things that the Act does allow you to do for the purposes of your own study, within reasonable limits, under what is known as “fair dealing”. You are advised not to copy beyond 5% of a book or one chapter, 1 poem or one article from a journal part.
Almost all the learning resources that you use as a student – books, journals, videos, software, etc. - will be covered by the Copyright, Designs and Patents Act 1988. This prohibits copying someone else's copyright material unless (a) you have their permission or (b) it falls within the limits allowed for “fair dealing
There will be times when you wish to include, or make reference to, material which is not your own (i.e. which is someone else’s copyright) when completing an assignment. It is legitimate to include quotations for the purposes of criticism and review, but you must make sure that such material is properly acknowledged or cited.
Shorter quotations of a few words or sentences may be used to illustrate a point, but not to replace using your own words. These must also be correctly acknowledged and cited.