abbastanza can be used like an adverb with the meaning of sufficiently or rather. for example: you are eating and you feel sufficiently full = ti senti abbastanza pieno. abbastanza means enough when you use it as an adjective for example: It's enough or it's sufficient = è abbastanza. basta is the third person of the verb "bastare" and we use it when we want to say that something it's enough or sufficient or we are pissed of something... for example: 1) è tardi! basta dormire! alzati! = it's late! stop sleeping! get up! 2) basta parlare! = stop talking! bastare = to be enough "mi basta che tu sia vicino a me" = it's enough you are next to me