Grappa is an exclusively Italian speciality, extracted from the pomace (= the rinds of pressed grapes).
Acquavit or Uvedilanga are two terms which you might have come across in connection with Grappa. Both names stand for another typical Italian speciality which is, strictly speaking, not Grappa. While Grappa is a pure pomace spirit, with Aquavit the whole fruit is used including the pulp, giving Aquavit a fruitier taste than that of Grappa.
Barrel ageing or not? A clear Grappa or Aquavit has no barrel ageing. If a bottled spirit has some colour already, then it is a barrel aged spirit. The longer the spirit ripens in the barrel, the more colour it acquires. A noble spirit with barrel ageing loses some of its fruitiness, yet it is rounder and sweeter. Most Grappa lovers prefer a barrel aged specimen to the white spirit, since its overall impression (nose – palate - aftertaste) is more harmonious.