observer vs perceiver

observer and perceiver both are nouns.

Word	Noun	Adjective	Verb	Adverb
observer	Yes	No	No	No
perceiver	Yes	No	No	No

As nouns, observer and perceiver are synonyms defined as:

observer and perceiver: a person who becomes aware (of things or events) through the senses

Other synonyms of observer include beholder, percipient.

observer (noun)	perceiver (noun)
a person who becomes aware (of things or events) through the senses	a person who becomes aware (of things or events) through the senses
an expert who observes and comments on something