She was lying on the beach", "she" is an endophoric expression because it refers to something mentioned elsewhere in the text, i.e. "Sally".
By contrast, "She was lying on the beach," if it appeared by itself, contains an exophoric expression; "she" refers to something that is not present in the surrounding text, so there is not enough information given within the text to independently determine to whom "she" refers.
Without further information, in other words, there is no way of knowing the exact meaning of an exophoric term.
Endophora can be broken into three subcategories: cataphora, anaphora and self-reference.
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