problem vs poser

problem and poser both are nouns.

Word	Noun	Adjective	Verb	Adverb
problem	Yes	No	No	No
poser	Yes	No	No	No

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

problem (noun)	poser (noun)
a source of difficulty	a particularly difficult or baffling question or problem
a question raised for consideration or solution	a person who poses for a photographer or painter or sculptor
a state of difficulty that needs to be resolved	a person who habitually pretends to be something he is not