"forse" means maybe or perhaps and expresses a doubt

"magari" could be translated in the same manner but in italian it is used in order to expres a wish or something we would like happen.

Ciao! "Magari potessi diventare ricco!" (I wish like to become rich.).

"Forse domani andrò dal dottore." (Maybe tomorrow I'm going to the physician.). --> you use "forse" when you are not sure about a thing. 

quando si usano le parole..?

ciao! mi sapresti dire quando si usano le parole "forse " e " magari " ?