grasping vs understanding

grasping and understanding both are nouns.

Word	Noun	Adjective	Verb	Adverb
grasping	Yes	Yes	No	No
understanding	Yes	Yes	No	No

As nouns, understanding is a hypernym of grasping; that is, understanding is a word with a broader meaning than grasping:

Other hypernyms of grasping include apprehension, discernment, savvy.

grasping (noun)	understanding (noun)
the act of gripping something firmly with the hands (or the tentacles)	the capacity for rational thought or inference or discrimination
understanding with difficulty	the cognitive condition of someone who understands
	an inclination to support or be loyal to or to agree with an opinion
	the statement (oral or written) of an exchange of promises

grasping (adjective)	understanding (adjective)
immoderately desirous of acquiring e.g. wealth	characterized by understanding based on comprehension and discernment and empathy