APA vs MLA vs Chicago: which referencing style do you need?
Referencing styles are not interchangeable. Each was designed for a different discipline and each has its own logic for showing where an idea came from. Using the wrong one is an easy mark to lose.
What each style is built for
APA (American Psychological Association) is used across the social sciences, psychology, education and many health courses. It values recency, so the year sits right next to the author.
MLA (Modern Language Association) is used in literature, languages and cultural studies. It values authorship, so the page number — not the year — is what appears in text.
Chicago is used in history, classics and much of the humanities. Its notes and bibliography variant uses footnotes, which lets you carry commentary as well as a reference.
How the in-text citation differs
APA puts author and year in brackets: (Beard, 2015, p. 112).
MLA puts author and page in brackets, with no year: (Beard 112).
Chicago notes and bibliography puts a number in the text that points to a footnote at the bottom of the page — which is why it is so common in history essays.
Harvard, OSCOLA, Turabian and Vancouver
Harvard is an author-date family, close in spirit to APA but with its own punctuation conventions. OSCOLA is the legal style used for law, and it uses footnotes with heavy abbreviation for cases and statutes. Turabian is a student-facing adaptation of Chicago, and in practice the two are nearly identical. Vancouver uses a numbered reference list, common in medicine and the sciences.
The practical test is simple: check your module handbook, then check which styles the department actually names. If it says "Chicago", confirming whether it means notes and bibliography or author-date will save you an entire rewrite.
Get the style right once
Set the citation style on the project, not on each individual source. Then every citation, footnote and bibliography entry in that assignment follows the same conventions, and changing style later reformats everything instead of forcing you to redo it by hand.