At its heart, Ila is nothing more than a search engine for finding backlinks to a given web resource represented by a URL. Backlinks are really just ordinary links viewed from the opposite end. An ordinary link is a reference from a source document to a destination document. Such a link is typically defined in the HTML text of the source document, e.g. using the familiar anchor element <a href="destination_url"> ..</a>.

From Ila's perspective, however, each link in the text of the source document defines two complementary links:

A given document's forelinks, then, correspond to the set of URLs the document references. It's backlinks, on the other hand, correspond to the set of URLs of documents that reference the given document. The situation is depicted in Figure 2.1.

Using Ila a user/application can query for the backlinks (a list of URLs for the documents represented with red boxes) of the target document (represented with the black box). Given Ila, a user is link aware. That is, a link aware user is able to "see" a plan view of the link structure of any web locality.