forest vs silva

forest and silva both are nouns.

Word	Noun	Adjective	Verb	Adverb
forest	Yes	No	Yes	No
silva	Yes	No	No	No

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

Other hyponyms of forest include greenwood, riparian forest, sylva, tree farm.

forest (noun)	silva (noun)
the trees and other plants in a large densely wooded area	the forest trees growing in a country or region
land that is covered with trees and shrubs

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