marking vs watermark

marking and watermark both are nouns.

Word	Noun	Adjective	Verb	Adverb
marking	Yes	No	No	No
watermark	Yes	No	No	No

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

marking: a distinguishing symbol
watermark: a distinguishing mark impressed on paper during manufacture; visible when paper is held up to the light

marking (noun)	watermark (noun)
evaluation of performance by assigning a grade or score	a distinguishing mark impressed on paper during manufacture; visible when paper is held up to the light
the act of making a visible mark on a surface	a line marking the level reached by a body of water
a pattern of marks
a distinguishing symbol