Harvard uses in-text author-date citations and a references list.
In your work, at every point in the text where a particular source is referred to by quoting or paraphrasing, include the author's surname and the year of publication along with page numbers if you are quoting these specifically.
For up to three authors include all names in the work, and if there are more than three, give the first author's surname and initials followed by et al, but include all authors' names in the references
If there is more than one work by a given author from the same year you can differentiate between them by adding "a", "b" etc. after the year
References are presented in alphabetical order by author's surname.
You should only include sources that you have referenced in your work.
If you are asked to include a bibliography (in addition to, or in place of, a references list) you can include further items that were read that informed your research and thinking for the assignment, in addition to those that you directly referenced.
How to reference using Harvard style
Detailed guidance is available for how to cite various types of resource in Harvard style.