A general term for cold soups made with local ingredients which, originally, included broken bread, olive oil, vinegar, garlic and water. The dish originated in Andalusia before being popularised by an Andalusian, Eugenia de Montijo, when she became Empress of France, a hundred years after the discovery of the New World had brought tomatoes to the old.
These days the term gazpacho outside Spain has come to mean cold tomato soup. Within Spain you might find either red or white gazpacho such as ajoblanco. Very rarely you might come across a green version made with peppers, spinach and coriander (US: cilantro). Spanish cooks would not generally use either cucumber or onion and would employ only a little garlic or green pepper, though gazpacho is often accompanied by a dish of finely chopped green peppers, cucumber, garlic and tomatoes.