saturation vs filling

saturation and filling both are nouns.

Word	Noun	Adjective	Verb	Adverb
saturation	Yes	No	No	No
filling	Yes	No	No	No

As nouns, filling is a hypernym of saturation; that is, filling is a word with a broader meaning than saturation:

saturation (noun)	filling (noun)
the act of soaking thoroughly with a liquid	the act of filling something
chromatic purity: freedom from dilution with white and hence vivid in hue	the yarn woven across the warp yarn in weaving
the process of totally saturating something with a substance	(dentistry) a dental appliance consisting of any of various substances (as metal or plastic) inserted into a prepared cavity in a tooth
a condition in which a quantity no longer responds to some external influence	a food mixture used to fill pastry or sandwiches etc.
	flow into something (as a container)
	any material that fills a space or container