REFERENCING is a way to demonstrate that you have extended your reading, learning and comprehension by using relevant and up to date sources.
Primary sources refer to the material the author has written, like all the works written by Shakespeare.
Secondary sources are written as interpretations, criticism, research, etc. about a subject or an author. An interpretation of Shakespeare’s tragedies will be categorised as secondary material on his tragedies. The tragedies themselves will be the primary sources. Source
What is citation?
A "citation" is the way you tell your readers that certain material in your work came from another source. It also gives your readers the information necessary to find that source again, including:
Why should I cite sources?
Giving credit to the original author by citing sources is the only way to use other people's work without plagiarizing. But there are a number of other reasons to cite sources:
Doesn't citing sources make my work seem less original?
Not at all. On the contrary, citing sources actually helps your reader distinguish your ideas from those of your sources. This will actually emphasize the originality of your own work.
When do I need to cite?
Whenever you borrow words or ideas, you need to acknowledge their source. The following situations almost always require citation: