marking vs marker

marking and marker both are nouns.

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

As nouns, marking and marker are synonyms defined as:

Other synonyms of marking include mark.

marking (noun)	marker (noun)
evaluation of performance by assigning a grade or score	some conspicuous object used to distinguish or mark something
the act of making a visible mark on a surface	a writing implement for making a mark
a pattern of marks	a distinguishing symbol
a distinguishing symbol