gradations — any process or change taking place through a series of stages, by degrees, or in a gradual manner.
hierarchies — any system of persons or things ranked one above another.
orders — an authoritative direction or instruction; command; mandate.
rules — a principle or regulation governing conduct, action, procedure, arrangement, etc.: the rules of chess.
series — a group or a number of related or similar things, events, etc., arranged or occurring in temporal, spatial, or other order or succession; sequence.
ways — manner, mode, or fashion: a new way of looking at a matter; to reply in a polite way.
trees — a plant having a permanently woody main stem or trunk, ordinarily growing to a considerable height, and usually developing branches at some distance from the ground.
