forest vs jungle

forest and jungle both are nouns.

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

Other hyponyms of forest include bosk, grove, rain forest, rainforest, monsoon forest, deciduous forest, old growth, virgin forest, second growth.

forest (noun)	jungle (noun)
the trees and other plants in a large densely wooded area	a location marked by an intense competition and struggle for survival
land that is covered with trees and shrubs	a place where hoboes camp
	an impenetrable equatorial forest

forest (verb)	jungle (verb)
establish a forest on previously unforested land