Oktoberfest vs festival

Oktoberfest and festival both are nouns.

Word	Noun	Adjective	Verb	Adverb
Oktoberfest	Yes	No	No	No
festival	Yes	No	No	No

As nouns, festival is a hypernym of Oktoberfest; that is, festival is a word with a broader meaning than Oktoberfest:

Oktoberfest: an autumn festival that involves merrymaking and drinking beer
festival: an organized series of acts and performances (usually in one place)

Other hypernyms of Oktoberfest include fete.

Oktoberfest (noun)	festival (noun)
an autumn festival that involves merrymaking and drinking beer	an organized series of acts and performances (usually in one place)
a strong lager made originally in Germany for the Oktoberfest celebration; sweet and copper-colored	a day or period of time set aside for feasting and celebration