The American Psychological Association (APA) citation style is the commonly used format for manuscripts in the social and health sciences.
APA style regulates style and formatting. These regulations try to make it so that all papers that are submitted for publication are evaluated based on the research involved, not on fancy graphics or writing ability. There are writing and grammar suggestions, as well, so that all manuscripts use similar writing styles and are free from bias.
The APA manual was recently updated to the 7th edition. The 7th edition has a Professional style and a Student style. We will be discussing the Professional style. Many resources on the internet are still using the 6th edition, or even earlier editions, so don’t trust them!