Referencing is acknowledging other's work or idea that you have used in your assignment. Always consult your course profile, assessment task sheets or lecturer for the preferred citation style for each course.
Referencing is stating where you got your information from; i.e. - your sources.
You reference to avoid being accused of plagiarism.
See the following pages for more information:
EndNote can be used to manage references, insert citations and generate lists of references.
There is an output style in EndNote for the Vancouver AMA Referencing Style. The Output styles page has instructions on downloading the file and where to place them.