Referencing is a standardised method of acknowledging the sources of information you have consulted. Anything - words, figures, theories, ideas, facts - originating from another source and used in your assignment must be referenced (i.e. acknowledged).
Referencing is done for the following reasons:
Let's look at an example:
You are writing an assignment about "Compiling a CV" and you consulted a book of J P Rendell, called "Getting that job: a guide to writing your own CV". In this book you have found a quotation that you want to include in your assignment. You do that as follows:
"Writing a CV is similar to writing a sales letter - you are, in fact, selling yourself - your skills and aptitudes." (Rendell, 1986:36). The following is an example of the bibliographic entry when using the Harvard Referencing Style:
Rendell, J.P. 1986. Getting that job: a guide to writing your own CV. 2nd ed. London: Clive Bingley