Referential Links: A third type of link is a referential link. It is associated to the associative link. Quite than representing a relationship among two related ideas, a referential link provides a link among an item of information and an explanation of such information. A simple illustration would be a link from a word to an explanation of that word. One easy way of understanding the dissimilarity between referential and associative links is that the items connected by an associative link can exist independently, although are related at a conceptual level.