White wine vinegar, as its name implies, is vinegar made from white wine. Wine vinegars tend to be milder and less acidic than cider or white distilled vinegar, so they make a great addition to sauces, salad dressing, and marinades.
You can substitute other vinegars like red wine vinegar (though it has a stronger flavor and may discolor a light dish), champagne vinegar, rice vinegar, or cider vinegar. Keep in mind that the acidity levels of these vinegars will vary, so adjust the amount used to taste.
Vinegar's flavor can have a big impact on the finished dish, so try different brands to see which you like best. Look for a balance of acidity and sweetness, a good depth of flavor that's assertive without being astringent.
Keep in a cool, dark place. Sealed it will keep indefinitely. Once opened, it should last about 6 months.