inflectional suffix vs ending

inflectional suffix and ending both are nouns.

Word	Noun	Adjective	Verb	Adverb
inflectional suffix	Yes	No	No	No
ending	Yes	No	No	No

As nouns, ending is a hypernym of inflectional suffix; that is, ending is a word with a broader meaning than inflectional suffix:

inflectional suffix: an inflection that is added at the end of a root word
ending: the end of a word (a suffix or inflectional ending or final morpheme)

Other hypernyms of inflectional suffix include termination.

inflectional suffix (noun)	ending (noun)
an inflection that is added at the end of a root word	the act of ending something
	the end of a word (a suffix or inflectional ending or final morpheme)
	the last section of a communication
	event whose occurrence ends something
	the point in time at which something ends