Here is an example of a perfect journal article reference from our database Academic Writer:
Ambrose, A. (1963). The age of onset of ambivalence in early infancy: Indications from the study of laughing. Journal of Child Psychology & Psychiatry, 4(3–4), 167–181. https://doi.org/10.1111/j.1469-7610.1963.tb02119.x
If you look closely and compare these two references, you'll see that every word in the title of the article is capitalized in the first example while only the first letter of the title and the first letter of the subtitle (after the colon) are capitalized in the correct reference from Academic Writer. In the first example, the article title is capitalized in what is called 'title case.' This is the only mistake. If every word is capitalized, this is called sentence case. Note that the journal title is capitalized using title case in both references.
This is the most common mistake for citation generators and humans to make, so always check whether your article title is in sentence or title case before you hand something in.