Counter admiral is a rank found in many navies of the world, but no longer used in English-speaking countries, where the equivalent rank is rear admiral. The term derives from the French contre-amiral. Depending on the country, it is either a one-star or two-star rank.
In modern navies that use it, rear (counter) admiral is generally, although not always, the lowest flag officer rank (in the German Navy, for instance, Flottillenadmiral ranks below Konteradmiral; in the Royal Canadian Navy, contre-amiral/rear admiral ranks above commodore).
In the navies of Portugal and Brazil, the rank of contra-almirante is the lowest of the permanent flag officer ranks. In the Portuguese Navy there is a flag officer rank below that of contra-almirante, the rank of comodoro (commodore), but this is only a provisional appointment, assigned to some captains.
Until the end of the 19th century, the present rank of contra-almirante was named chefe de esquadra (chief of squadron), both in the Portuguese and the Brazilian navies.