Vinegar is a liquid containing mainly water and acetic acid and used mostly in cooking. It can be made from wine or other liquids containing alcohol, like cider, fermented fruit juices, or fermented malt. Ethanol is oxidized from the liquid, resulting in vinegar.
Vinegar made from dates is a traditional product of the Middle East. It can also be made through the use of certain bacteria. Vinegar contains about 5% of Acetic acid. The acid makes it sour.
In cooking, it is often used as a condiment to add to salad, fish, french fries and vegetables like pickles and cabbage. It is much used in salad dressings.
The pH of vinegar depends on how much acid is in it. Apple cider vinegar is typically between pH 4.25 and 5.00 if undiluted. Distilled vinegar has a pH of around 2.4.