symbolisation vs emblem

symbolisation and emblem both are nouns.

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

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

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

Other hyponyms of symbolisation include crossbones, cornucopia, horn of plenty, death's head, oriflamme, white feather, allegory.

symbolisation (noun)	emblem (noun)
the practice of investing things with symbolic meaning	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
the use of symbols to convey meaning