When citing, you need to select a style, and use that consistently through your essay, paper or thesis.
At the VCA Chicago 16 A Footnoting Style is used by all Schools. The School of Film and Television will allow Harvard - in text - style as well.
Citations occur throughout/at the end of the paper, every time you refer to, or directly quote something you have read. You will also have a bibliography consisting of everything you have read or referred to in your research
Some styles use footnotes or endnotes (citations at the bottom of the page, or at the end of the paper) other styles use in-text citations (citations are next to the text in the body of the paper).
To find out what style is used in your discipline, ask your lecturers.
For information on citation styles see the following: