fasting vs Ramadan

fasting and Ramadan both are nouns.

Word	Noun	Adjective	Verb	Adverb
fasting	Yes	No	No	No
Ramadan	Yes	No	No	No

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

fasting: abstaining from food
Ramadan: (Islam) a fast (held from sunrise to sunset) that is carried out during the Islamic month of Ramadan

Other hyponyms of fasting include diet, dieting, hunger strike.

fasting (noun)	Ramadan (noun)
abstaining from food	(Islam) a fast (held from sunrise to sunset) that is carried out during the Islamic month of Ramadan
	the ninth month of the Islamic calendar; the month of fasting; the holiest period for the Islamic faith