Each discipline follows a specific writing “style.” By sticking to the correct style, you help your reader navigate your writing. Each style has clear rules that govern such things as
page format
identification of sources
tense and point-of-view
Each style has its own handbook which are revised regularly, often in response to technology advances. The ASC has copies of these handbooks for reference. If you prefer to use an online resource, the Purdue OWL is good.
MLA style is used most often in the liberal arts and humanities.
APA style (and ASA) is used most often in the social sciences.
ASA style is used in sociology.
CMS style is used most often in scholarly writing in history and art history.