In meaning there's no difference all of them means "good" (masculine). But in polish we have declination that applies either to nouns or to adjectives. They are just declined forms of the same word "dobry". If you want to get known more about polish, ask me.

cosi' in italiano: buono, buona, etc. Noi diciamo: Mam dobre jabłko = Ho una buona mela. Mam dobrego męża. = Ho un buon marito. Capisci bene? Ciao, Cześć