Helen needed the book and asked me to hurry up with it.
Here, it is anaphoric because it refers back to the noun book.
The term is also used for the repetition of words or phrases for rhetorical effect:
We shall not give in; we shall not falter; we shall not surrender.
Here, the repetition of we shall not is anaphoric.
Browse the following links to other content related to the term 'Anaphora' from the 'Functions & Text' grammar category: