The name of my favorite condiment comes from the Latin acetum, which in turn comes from the adjective acer, meaning sour. Fermentation of ethanol produces acetic acid, which gives vinegar its characteristic flavor.
The vinegar most commonly used in Italy is aceto di vino, which is important both as an ingredient and as a preserving medium: pickled vegetables are called sottaceti.
Aceto balsamico, a product typical of Modena and Reggio Emilia, is made with must and is aged in wood casks.
My mother uses home-made vinegar from wine-making friends or relatives. It is so strong that you only need a splash. Failure to control the dosing hand will result in an inedible dish.