symphony orchestra vs orchestra

symphony orchestra and orchestra both are nouns.

Word	Noun	Adjective	Verb	Adverb
symphony orchestra	Yes	No	No	No
orchestra	Yes	No	No	No

As nouns, orchestra is a hypernym of symphony orchestra; that is, orchestra is a word with a broader meaning than symphony orchestra:

symphony orchestra: a large orchestra; can perform symphonies
orchestra: a musical organization consisting of a group of instrumentalists including string players

symphony orchestra (noun)	orchestra (noun)
a large orchestra; can perform symphonies	seating on the main floor in a theater
	a musical organization consisting of a group of instrumentalists including string players