What’s the difference between Harvard and Vancouver referencing styles?

Harvard referencing uses an author–date system. Sources are cited by the author’s last name and the publication year in brackets. Each Harvard in-text citation corresponds to an entry in the alphabetised reference list at the end of the paper.

Vancouver referencing uses a numerical system. Sources are cited by a number in parentheses or superscript. Each number corresponds to a full reference at the end of the paper.

Harvard style Vancouver style
In-text citation Each referencing style has different rules (Pears and Shields, 2019). Each referencing style has different rules (1).
Reference list Pears, R. and Shields, G. (2019). Cite them right: The essential referencing guide. 11th edn. London: MacMillan. 1. Pears R, Shields G. Cite them right: The essential referencing guide. 11th ed. London: MacMillan; 2019.