Skin-contact (AKA "Orange") wines are white wines made like red wines.
Typically, white wines are fermented without the grape skins - giving them that cleaner and crisper finish. On the other hand, red wines are fermented with the grape skin on - providing them with those tannins that create that dry desert-y feeling on your tongue.
Skin-contact wines ferment with their grape skins, which give the wine a deeper color and flavor. Depending on how long the juice ferments with the skins—anywhere from a few hours to many months—skin-contact wines can range from golden-straw yellow, to opaque amber or Tony the Tiger orange (depending on the grape). The time with the skins also gives these wines more red wine characteristics - like bigger body and more tannins, while maintaining the balanced acidity of a white wine.
Rule of thumb is the longer the skins hang with the juice, the bigger and bolder the wine. You can expect a few days of skin contact to be lighter, while those that are skin-fermented two weeks and beyond will be a lot more complex. This means you can end up with lighter skin-contact wines whose taste is reminiscent of bright citrus juice, or heavier ones that can be as bold as dessert wine.
Skin-contact wines are very much associated with the natural wine movement, as they're a revival of "the old way" white wines were made. Archeological evidence suggests that skin-contact wines were enjoyed in Georgia (the country, not the state) as far back as 10,000 years ago. While wine regions all over the world are currently producing a wide variety of orange wines, they have been typically enjoyed in the central part of Europe - including the Veneto region of Italy, Austria, and Slovenia.