APA uses two types of capitalization: title case and sentence case.

Title case. Capitalize the following: the first word in a title, the first word of a subtitle or after a colon, proper nouns, major words, and words of four letters or more. In references, title case is used for the names of journals, magazines, and newspapers.

Issues in Informing Science and Information Technology (the title of a journal)

Sentence case. Capitalize only the following: the first word in a title, the first word of a subtitle, the first work after a colon, dash, or end punctuation in the heading, and proper nouns. All other words are in lowercase. In references, sentence case is used for the titles of articles in a journal, the titles of books, and the titles of chapters in a book.

Constructionism in practice: Designing, thinking, and learning in a digital world

Publication manual of the American Psychological Association

Research and PhD capacities in Africa: Kenya report