Cataphorism is a grammatical expression that refers to a word or a phrase that links to another word or phrase which was used after in the same text
If you call him, tell Sam to come as soon as possible.
In the above example, him is the cataphoric reference to Sam as it is used before Sam and refer to the same person.
The use of such terms (words or phrases) that are referring forward to something said or written afterwards in the same text is termed as cataphoric reference.
They were all sitting quietly, all students was speechless.
In the above example, they is used as a cataphora and is a cataphoric reference to students. Note that both they and students refer to the same collective noun and the noun students is used afterwards.
Despite referring to nouns, cataphoric reference can also be used to refer other ideas used forward in the same text.
It is everyone’s favorite subject. Advanced psychology is in demand these days.
In the above example, it is is an example of anaphoric reference which refers forward to Advanced Psychology.