A similarity of both transitions to democracy was than both resulted in a movement from inside of the country, in Poland by "Solidarnosc" - Solidarity, a movement of workers, and in Chile through a general plebiscite in which the citizens voted against Pinochet. Also they happened at a close time and were part of the general movement towards democracy.
A difference was for example the previous regime: right-wing in Chile and left-wing in Poland.