Concept Clarification

As simple as it sounds, can you please tell me the simplest difference between eluviation and illuviation? As far as I know, they are both a movement of soil matter in the soil horizons right?? (And they are both downward movements??)

One way to think about eluviation is "washing out" and illuviation as "washing in". Thus Ae is an eluviated A horizon - where organic matter, clay or Al/Fe oxides may be eluviated (or washed out) of the A horizon. Illuvial horizons include Bt, Bf, Bh where clay, Fe/Al oxides or organic colloids are "washed in" or accumulate.