The answer is that it indicated the order of "greater importance".
A hierarchy refers to an arrangement of things (objects, names, values, classes, and so on.) in which the things are represented to as being "above", "beneath", or "at an indistinguishable level from" each other. A hierarchy can connect elements either specifically or in a roundabout way, and either vertically or diagonally. Authoritative structures exist that are both unconventional and correlative to hierarchy.