Before we explain a bit more about referencing here are some definitions to get you started.
A citation is the ‘indicator’ you put in the text to alert the reader to the fact you are talking about somebody else’s work or using somebody else’s words. The ‘indicator’ often takes the form of a number, either in brackets or as a superscript, or it can state the surname of the author with the year of publication, e.g. (Brown, 2009).
A reference is a detailed description of the source you have cited. References are often at the bottom of a page or collected together at the end of an article as a reference list.
A bibliography is a list of the materials, such as books and journal articles, that you have used. In some disciplines it may include only the items you have used as general reading to provide background information but not necessarily cited because individual ideas or text are not reproduced. In other disciplines it may include both the information you have used for background reading and your reference list.