The domestic pig is usually given the scientific name Sus scrofa. Some authors call it S. domesticus, but most consider it to be just a domesticated version of the wild boar, S. scrofa and not a separate species or even sub-species. The pig appears to have been domesticated about 5,000 years ago in several different places independently of each other, unlike the cow which was domesticated in what is now Iraq and then spread. The wild boar has a natural range across most of the 'old world' from England to Japan, North Africa to Southeast Asia, and has been introduced or escaped from captivity and 'reverted' to the wild state in the Americas. Most domestic animals are called 'feral' when the go back to the wild, but retaining most of their domestic features, but the pig actually does become wild again, though usually still called feral in the US at least to distinguish it from introduced wild individuals. The wild boar is more muscular, leaner, and taller than his domestic cousin, it has longer coarser hair and longer canines, tusks or 'tushes.' The tusks are usually removed in domestic pigs but even so they don't grow as long as they would in the same pig gone wild. In fact this reverting to the wild state can happen in an individual animal rather than taking place over generations. Now to answer your question, the typical habitat of the wild boar and most favorable for his feral cousins is generally moist forests,especially oak forests ( acorns are a favorite food), shrub-lands, tall grass lands, and areas where reeds are abundant. They like areas with high undergrowth where they can stay hidden but with nearby more open areas for foraging. Very important is a nearby source of water or at least mud, Sus scrofa is prone to heatstroke in warm temperature, they wallow in mud or water to maintain a comfortable temperature and as protection from sunburn and insect bites. Just like their farm cousin. And just like them the wild boar eats nearly anything, shrubs, grass, weeds, bird eggs, snakes ( domestic pigs are great snake killers too), grasshoppers, mice, baby and young rabbits,roots, tubers, seeds, nuts, acorns, mushrooms, ( domestic pigs are used to hunt truffles) carrion,( as recently as the 19th century soldiers feared dying in battle and being eaten by wild boars), even manure. Some pigs seem to have adapted to the fairytale habitat where they apparently construct shelters of straw, sticks, even brick. At least one has adapted to Hollywood where his animated habitat includes an insane black duck.