ordering vs grading

ordering and grading both are nouns.

Word	Noun	Adjective	Verb	Adverb
ordering	Yes	No	No	No
grading	Yes	No	No	No

As nouns, grading is a hyponym of ordering; that is, grading is a word with a more specific, narrower meaning than ordering:

Other hyponyms of ordering include rank order, scaling, sequence, succession, layout, alphabetisation, alphabetization.

ordering (noun)	grading (noun)
the act of putting things in a sequential arrangement	the act of arranging in a graduated series
logical or comprehensible arrangement of separate elements	evaluation of performance by assigning a grade or score
	changing the ground level to a smooth horizontal or gently sloping surface