emblem vs symbol

emblem and symbol both are nouns.

Word	Noun	Adjective	Verb	Adverb
emblem	Yes	No	No	No
symbol	Yes	No	No	No

As nouns, symbol is a hypernym of emblem; that is, symbol is a word with a broader meaning than emblem:

emblem: a visible symbol representing an abstract idea
symbol: something visible that by association or convention represents something else that is invisible

Other hypernyms of emblem include symbolic representation, symbolisation, symbolization.

emblem (noun)	symbol (noun)
special design or visual object representing a quality, type, group, etc.	something visible that by association or convention represents something else that is invisible
a visible symbol representing an abstract idea	an arbitrary sign (written or printed) that has acquired a conventional significance