This document introduces referencing and why it is important. It defines referencing as providing citations for direct quotes, data, or ideas from other sources to avoid plagiarism and give credit. There are two main referencing styles - author-date which lists sources alphabetically by author in a reference list, and numerical which numbers sources in the order they appear in text. Reasons to reference include informing readers of sources used, giving credibility to arguments, and attributing theories or models to their originators. Plagiarism is defined as passing off another's work as one's own. Common knowledge and your own ideas do not need to be referenced.