Pisco is a brandy, originating in either Peru or Chile a fact which is still hotly debated today, as well who 'owns' the right to call themselves the founder of the famous cocktail, The Pisco Sour.
Pisco is produced by distilling the local grape-wine into a high alcohol spirit, using copper-pot stills, like those used in the production of whisky, and is then aged for a minimum of 3 months in glass or stainless steel, but which must not be aged in any other container that may alter its 'pure' properties.
It is most likely that pisco takes it's name form the Peruvian coastal town of the same name, in the valley of Pisco, aside the river Pisco and would be the strongest of arguments versus Chile, especially as this is where many of the area's best vineyards are.
In the 16th century, it was the Spaniards who ruled their countries, and it was they who first planted grape vines in South America, only to find their own home-grown product threatened by South America's own production, and it is then when pisco production soared and which replaced the alternative to the Spaniard's own imported pomace brandy.
There a four types of Pisco produced. 'Puro' which is made form a single grape variety, mostly Quebranta. Then there's Aromaticas, alike to Italian grappas where aromatic grape types like Muscat are used. Thirdly there is Acholado, meaning multi-varietal where the must of several grape varieties are used. Lastly, Most Verde (green must) where only one type of grape must may be used.