Campari is an alcoholic apéritif (20.5%, 21%, 25% or 28% ABV, depending on the country in which it is sold) obtained from the infusion of herbs and fruit (including chinotto) in alcohol and water. It is a bitters characterized by its dark red color.
Campari is often used in cocktails and is commonly served with soda water, wine, or citrus juice. It is produced by the Campari Group, a multi-national company based in Italy.
Info gleaned from Wikipedia