The Mapuche are a group of indigenous inhabitants of south-central Chile and southwestern Argentina, including parts of present-day Patagonia. The collective term refers to a wide-ranging ethnicity composed of various groups who shared a common social, religious and economic structure, as well as a common linguistic heritage as Mapudungun speakers. Their influence once extended from the Aconcagua River to the Chiloé Archipelago and spread later eastward to the Argentine pampa. Today the collective group makes up over 80% of the indigenous peoples in Chile, and about 9% of the total Chilean population. They are particularly concentrated in Araucanía. Many have migrated to the Santiago area for economic opportunities.