The word aji has been used in the Andean region since long before the conquistadors arrived. It then spread along with the Capsicum fruit from Central and south America to other pepper growing regions.
Capsicum baccatum is still referred to as ají, while other peppers are referred to as chile pepper from the Spanish observation of the similarity to the black pepper's heat sensation.
The c. baccatum species, most notably aji amarillo and aji panca, is considered one of the three main condiments of the Andean cuisine, together with red onion and cilantro. It is indispensable when preparing the Peruvian stew Ají de gallina ("Chile Chicken"), Papa a la Huancaína, Causa Rellena, Seco de carne, and ceviche among others.
In Ecuador, ají amarillo, onion, and lemon juice is served in a separate bowl with many meals as an optional condiment.