politics vs geopolitics

politics and geopolitics both are nouns.

Word	Noun	Adjective	Verb	Adverb
politics	Yes	No	No	No
geopolitics	Yes	No	No	No

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

politics: the study of government of states and other political units
geopolitics: the study of the effects of economic geography on the powers of the state

Other hyponyms of politics include practical politics, realpolitik.

politics (noun)	geopolitics (noun)
the profession devoted to governing and to political affairs	the study of the effects of economic geography on the powers of the state
the activities and affairs involved in managing a state or a government
the study of government of states and other political units
the opinion you hold with respect to political questions
social relations involving intrigue to gain authority or power