Vinegar is a liquid that's commonly used in cooking for its tart, acidic flavor. You're probably familiar with the taste of vinegar from things like salad dressing and pickles.
While you might not want to drink a glass of vinegar, it's a useful ingredient in many recipes, both for its flavor, which varies depending on how it's made, and its tenderizing properties. Vinegar can also be used for cleaning, freshening laundry, killing pests, and taking the sting off a bite from a jellyfish or wasp, among many other uses. Vinegar means "sour wine," and that's exactly what it is— juice that's fermented way beyond wine.