What are the subjects and partners in photographic composition?

The subject is the main thing you want to express when shooting. For example, when shooting portraits, people are the main body of shooting; When shooting a scene, the scene to be shot is the main body.

Accompaniment is not common, it is used to set off the main body and highlight the main body, which is also commonly known as the background. When shooting a composition, all the scenes in the photo range except the main body can be called the background.