Not necessarily and it depends on the region. If it's a wine region, yes, they usually make it from distilled wine. Otherwise it's made from fruit. Or both. For instance after one squeezes the grapes for wine, the leftover pulp and skin is used to make grape brandy (tescovina). Also leftover wine from filtering or from a barrel that was left less than half empty for a longer period and the wine oxydized is distilled to make wine brandy (vinars). They taste differently and are called differently. Tescovina has a more fruity flavour, while vinars tastes like pure alcohol with a mild grape skin or seed flavour. Other brandies in other regions are made mostly from fruit, either distilled once (rachiu, tuica) or twice (palinca) depending on the region. Usually in the north you have double distillation (like in Hungary) and in the south they distill it only once (like in Greece). And then of course there's grain alcohol but that's almost never home made but rather industrially produced. It's used to produce home made sweet fruit brandies from sour cherries or wild berries.
Dunno about grappa, but vinars is distilled wine which is either consumed directly or used to make cognac by aging it in oak casks or with oak splinters and maybe adding some additional ingredients such as vanilla, black tea or Sambucus flower infusion. It really depends on the producer and the recipe, but home made cognac is made like that. Each producer obviously has their own recipe. The best I've had was just aged in an oak barrel for 15y. It had a mild amberish colour. The ones made with splinters or wood residue have a too pronounced oak taste.
Yes, or a kind of cognac -- also "vinars" comes from "vin ars", literally meaning "burnt wine", possibly a mirror translation of "Weinbrand" in german or transylvanian saxon dialects.
