During fermentation, yeast converts grapes’ natural sugars into alcohol. By halting fermentation before all the sugar is converted, some “residual sugar” will remain, making a sweeter wine.
Obviously, the more residual sugar, the sweeter the wine. Other ways to sweeten wine include adding sugar, either before or after fermentation, or removing water through drying or freezing to concentrate the sugar.
Sweet wine is the opposite of dry. But the perception of sweetness can be deceptive. For example, fruity flavors make a wine seem sweeter, even if it’s dry, while high tannins or acidity make a sweet wine taste dry.
Of course, preference is subjective, too. Check out Maize Valley’s sweet wines to find one that fits your tastes.