Representing: Something A represents something B if and only if the properties, relations and elements of A are systematically correlated with the properties, relations and elements of B in such a way that - some of - the latter can be inferred from the former for those who know the correlation.
This seems to be a uniquely human abillity in so far as it depends on the human ability to reason with symbols. In logic and mathematics relations that represent are isomorphisms or morphisms.
The idea that something A represents something B is very fundamental and occurs in many forms.
An often useful instance of representing is a map that represents some territory.
See: Formalizations of representing, Map