1. A method of presenting content indicative of one or more entities which contributed to a window being displayed using a processing system, wherein the method comprises: (a) setting the window as a starting entity; (b) determining one or more properties of the starting entity; (c) identifying, using the one or more properties and at least one rule, one or more entities related to the starting entity which contributed to the window being displayed; and (d) providing to a user, using the processing system, content indicative of the one or more entities which contributed to the window being displayed.